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2018 |
Ferreira, Flávia Viana; Aguiar, Eric Roberto Guimarães Rocha; Olmo, Roenick Proveti; de Oliveira, Karla Pollyanna Vieira; Silva, Emanuele Guimarães; Sant'Anna, Maurício Roberto Viana; de Gontijo, Nelder Figueiredo; Kroon, Erna Geessien; Imler, Jean-Luc; Marques, João Trindade The small non-coding RNA response to virus infection in the Leishmania vector Lutzomyia longipalpis Article de journal PLoS Negl Trop Dis, 12 (6), p. e0006569, 2018, ISSN: 1935-2735. Résumé | Liens | BibTeX | Étiquettes: Animals, Host-Pathogen Interactions, imler, Insect Vectors, Leishmania, M3i, ncRNA, Psychodidae, RNA, RNA Interference, Small Interfering, Untranslated, Vesicular stomatitis Indiana virus, Viral @article{ferreira_small_2018, title = {The small non-coding RNA response to virus infection in the Leishmania vector Lutzomyia longipalpis}, author = {Flávia Viana Ferreira and Eric Roberto Guimarães Rocha Aguiar and Roenick Proveti Olmo and Karla Pollyanna Vieira de Oliveira and Emanuele Guimarães Silva and Maurício Roberto Viana Sant'Anna and Nelder Figueiredo de Gontijo and Erna Geessien Kroon and Jean-Luc Imler and João Trindade Marques}, doi = {10.1371/journal.pntd.0006569}, issn = {1935-2735}, year = {2018}, date = {2018-01-01}, journal = {PLoS Negl Trop Dis}, volume = {12}, number = {6}, pages = {e0006569}, abstract = {Sandflies are well known vectors for Leishmania but also transmit a number of arthropod-borne viruses (arboviruses). Few studies have addressed the interaction between sandflies and arboviruses. RNA interference (RNAi) mechanisms utilize small non-coding RNAs to regulate different aspects of host-pathogen interactions. The small interfering RNA (siRNA) pathway is a broad antiviral mechanism in insects. In addition, at least in mosquitoes, another RNAi mechanism mediated by PIWI interacting RNAs (piRNAs) is activated by viral infection. Finally, endogenous microRNAs (miRNA) may also regulate host immune responses. Here, we analyzed the small non-coding RNA response to Vesicular stomatitis virus (VSV) infection in the sandfly Lutzoymia longipalpis. We detected abundant production of virus-derived siRNAs after VSV infection in adult sandflies. However, there was no production of virus-derived piRNAs and only mild changes in the expression of vector miRNAs in response to infection. We also observed abundant production of virus-derived siRNAs against two other viruses in Lutzomyia Lulo cells. Together, our results suggest that the siRNA but not the piRNA pathway mediates an antiviral response in sandflies. In agreement with this hypothesis, pre-treatment of cells with dsRNA against VSV was able to inhibit viral replication while knock-down of the central siRNA component, Argonaute-2, led to increased virus levels. Our work begins to elucidate the role of RNAi mechanisms in the interaction between L. longipalpis and viruses and should also open the way for studies with other sandfly-borne pathogens.}, keywords = {Animals, Host-Pathogen Interactions, imler, Insect Vectors, Leishmania, M3i, ncRNA, Psychodidae, RNA, RNA Interference, Small Interfering, Untranslated, Vesicular stomatitis Indiana virus, Viral}, pubstate = {published}, tppubtype = {article} } Sandflies are well known vectors for Leishmania but also transmit a number of arthropod-borne viruses (arboviruses). Few studies have addressed the interaction between sandflies and arboviruses. RNA interference (RNAi) mechanisms utilize small non-coding RNAs to regulate different aspects of host-pathogen interactions. The small interfering RNA (siRNA) pathway is a broad antiviral mechanism in insects. In addition, at least in mosquitoes, another RNAi mechanism mediated by PIWI interacting RNAs (piRNAs) is activated by viral infection. Finally, endogenous microRNAs (miRNA) may also regulate host immune responses. Here, we analyzed the small non-coding RNA response to Vesicular stomatitis virus (VSV) infection in the sandfly Lutzoymia longipalpis. We detected abundant production of virus-derived siRNAs after VSV infection in adult sandflies. However, there was no production of virus-derived piRNAs and only mild changes in the expression of vector miRNAs in response to infection. We also observed abundant production of virus-derived siRNAs against two other viruses in Lutzomyia Lulo cells. Together, our results suggest that the siRNA but not the piRNA pathway mediates an antiviral response in sandflies. In agreement with this hypothesis, pre-treatment of cells with dsRNA against VSV was able to inhibit viral replication while knock-down of the central siRNA component, Argonaute-2, led to increased virus levels. Our work begins to elucidate the role of RNAi mechanisms in the interaction between L. longipalpis and viruses and should also open the way for studies with other sandfly-borne pathogens. |
2015 |
Aguiar, Eric Roberto Guimarães Rocha; Olmo, Roenick Proveti; Paro, Simona; Ferreira, Flavia Viana; da de Faria, Isaque João Silva; Todjro, Yaovi Mathias Honore; Lobo, Francisco Pereira; Kroon, Erna Geessien; Meignin, Carine; Gatherer, Derek; Imler, Jean-Luc; Marques, João Trindade Sequence-independent characterization of viruses based on the pattern of viral small RNAs produced by the host Article de journal Nucleic Acids Research, 43 (13), p. 6191–6206, 2015, ISSN: 1362-4962. Résumé | Liens | BibTeX | Étiquettes: Animals, Contig Mapping, Female, imler, insects, M3i, meignin, Ovary, Plants, RNA, Sequence Analysis, Small Untranslated, Vertebrates, Viral, Viral Tropism, viruses @article{aguiar_sequence-independent_2015, title = {Sequence-independent characterization of viruses based on the pattern of viral small RNAs produced by the host}, author = {Eric Roberto Guimarães Rocha Aguiar and Roenick Proveti Olmo and Simona Paro and Flavia Viana Ferreira and Isaque João Silva da de Faria and Yaovi Mathias Honore Todjro and Francisco Pereira Lobo and Erna Geessien Kroon and Carine Meignin and Derek Gatherer and Jean-Luc Imler and João Trindade Marques}, url = {http://nar.oxfordjournals.org/lookup/doi/10.1093/nar/gkv587}, doi = {10.1093/nar/gkv587}, issn = {1362-4962}, year = {2015}, date = {2015-07-01}, journal = {Nucleic Acids Research}, volume = {43}, number = {13}, pages = {6191--6206}, abstract = {Virus surveillance in vector insects is potentially of great benefit to public health. Large-scale sequencing of small and long RNAs has previously been used to detect viruses, but without any formal comparison of different strategies. Furthermore, the identification of viral sequences largely depends on similarity searches against reference databases. Here, we developed a sequence-independent strategy based on virus-derived small RNAs produced by the host response, such as the RNA interference pathway. In insects, we compared sequences of small and long RNAs, demonstrating that viral sequences are enriched in the small RNA fraction. We also noted that the small RNA size profile is a unique signature for each virus and can be used to identify novel viral sequences without known relatives in reference databases. Using this strategy, we characterized six novel viruses in the viromes of laboratory fruit flies and wild populations of two insect vectors: mosquitoes and sandflies. We also show that the small RNA profile could be used to infer viral tropism for ovaries among other aspects of virus biology. Additionally, our results suggest that virus detection utilizing small RNAs can also be applied to vertebrates, although not as efficiently as to plants and insects.}, keywords = {Animals, Contig Mapping, Female, imler, insects, M3i, meignin, Ovary, Plants, RNA, Sequence Analysis, Small Untranslated, Vertebrates, Viral, Viral Tropism, viruses}, pubstate = {published}, tppubtype = {article} } Virus surveillance in vector insects is potentially of great benefit to public health. Large-scale sequencing of small and long RNAs has previously been used to detect viruses, but without any formal comparison of different strategies. Furthermore, the identification of viral sequences largely depends on similarity searches against reference databases. Here, we developed a sequence-independent strategy based on virus-derived small RNAs produced by the host response, such as the RNA interference pathway. In insects, we compared sequences of small and long RNAs, demonstrating that viral sequences are enriched in the small RNA fraction. We also noted that the small RNA size profile is a unique signature for each virus and can be used to identify novel viral sequences without known relatives in reference databases. Using this strategy, we characterized six novel viruses in the viromes of laboratory fruit flies and wild populations of two insect vectors: mosquitoes and sandflies. We also show that the small RNA profile could be used to infer viral tropism for ovaries among other aspects of virus biology. Additionally, our results suggest that virus detection utilizing small RNAs can also be applied to vertebrates, although not as efficiently as to plants and insects. |
Paro, Simona; Imler, Jean-Luc; Meignin, Carine Sensing viral RNAs by Dicer/RIG-I like ATPases across species Article de journal Current Opinion in Immunology, 32 , p. 106–113, 2015, ISSN: 1879-0372. Résumé | Liens | BibTeX | Étiquettes: Adenosine Triphosphatases, Animals, DEAD-box RNA Helicases, Humans, imler, M3i, meignin, Protein Binding, Protein Interaction Domains and Motifs, Ribonuclease III, RNA, Viral, Virus Diseases, viruses @article{paro_sensing_2015, title = {Sensing viral RNAs by Dicer/RIG-I like ATPases across species}, author = {Simona Paro and Jean-Luc Imler and Carine Meignin}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0952791515000102}, doi = {10.1016/j.coi.2015.01.009}, issn = {1879-0372}, year = {2015}, date = {2015-02-01}, journal = {Current Opinion in Immunology}, volume = {32}, pages = {106--113}, abstract = {Induction of antiviral immunity in vertebrates and invertebrates relies on members of the RIG-I-like receptor and Dicer families, respectively. Although these proteins have different size and domain composition, members of both families share a conserved DECH-box helicase domain. This helicase, also known as a duplex RNA activated ATPase, or DRA domain, plays an important role in viral RNA sensing. Crystallographic and electron microscopy studies of the RIG-I and Dicer DRA domains indicate a common structure and that similar conformational changes are induced by dsRNA binding. Genetic and biochemical studies on the function and regulation of DRAs reveal similarities, but also some differences, between viral RNA sensing mechanisms in nematodes, flies and mammals.}, keywords = {Adenosine Triphosphatases, Animals, DEAD-box RNA Helicases, Humans, imler, M3i, meignin, Protein Binding, Protein Interaction Domains and Motifs, Ribonuclease III, RNA, Viral, Virus Diseases, viruses}, pubstate = {published}, tppubtype = {article} } Induction of antiviral immunity in vertebrates and invertebrates relies on members of the RIG-I-like receptor and Dicer families, respectively. Although these proteins have different size and domain composition, members of both families share a conserved DECH-box helicase domain. This helicase, also known as a duplex RNA activated ATPase, or DRA domain, plays an important role in viral RNA sensing. Crystallographic and electron microscopy studies of the RIG-I and Dicer DRA domains indicate a common structure and that similar conformational changes are induced by dsRNA binding. Genetic and biochemical studies on the function and regulation of DRAs reveal similarities, but also some differences, between viral RNA sensing mechanisms in nematodes, flies and mammals. |
2014 |
Chtarbanova, Stanislava; Lamiable, Olivier; Lee, Kwang-Zin; Galiana, Delphine; Troxler, Laurent; Meignin, Carine; Hetru, Charles; Hoffmann, Jules A; Daeffler, Laurent; Imler, Jean-Luc Drosophila C virus systemic infection leads to intestinal obstruction Article de journal Journal of Virology, 88 (24), p. 14057–14069, 2014, ISSN: 1098-5514. Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, Dicistroviridae, Female, Gastrointestinal Tract, Gene Expression Profiling, hoffmann, imler, Intestinal Obstruction, M3i, meignin, Muscle, Nodaviridae, Sindbis Virus, Smooth, Viral Tropism @article{chtarbanova_drosophila_2014, title = {Drosophila C virus systemic infection leads to intestinal obstruction}, author = {Stanislava Chtarbanova and Olivier Lamiable and Kwang-Zin Lee and Delphine Galiana and Laurent Troxler and Carine Meignin and Charles Hetru and Jules A Hoffmann and Laurent Daeffler and Jean-Luc Imler}, url = {http://jvi.asm.org/content/88/24/14057}, doi = {10.1128/JVI.02320-14}, issn = {1098-5514}, year = {2014}, date = {2014-12-01}, journal = {Journal of Virology}, volume = {88}, number = {24}, pages = {14057--14069}, abstract = {Drosophila C virus (DCV) is a positive-sense RNA virus belonging to the Dicistroviridae family. This natural pathogen of the model organism Drosophila melanogaster is commonly used to investigate antiviral host defense in flies, which involves both RNA interference and inducible responses. Although lethality is used routinely as a readout for the efficiency of the antiviral immune response in these studies, virus-induced pathologies in flies still are poorly understood. Here, we characterize the pathogenesis associated with systemic DCV infection. Comparison of the transcriptome of flies infected with DCV or two other positive-sense RNA viruses, Flock House virus and Sindbis virus, reveals that DCV infection, unlike those of the other two viruses, represses the expression of a large number of genes. Several of these genes are expressed specifically in the midgut and also are repressed by starvation. We show that systemic DCV infection triggers a nutritional stress in Drosophila which results from intestinal obstruction with the accumulation of peritrophic matrix at the entry of the midgut and the accumulation of the food ingested in the crop, a blind muscular food storage organ. The related virus cricket paralysis virus (CrPV), which efficiently grows in Drosophila, does not trigger this pathology. We show that DCV, but not CrPV, infects the smooth muscles surrounding the crop, causing extensive cytopathology and strongly reducing the rate of contractions. We conclude that the pathogenesis associated with systemic DCV infection results from the tropism of the virus for an important organ within the foregut of dipteran insects, the crop. IMPORTANCE: DCV is one of the few identified natural viral pathogens affecting the model organism Drosophila melanogaster. As such, it is an important virus for the deciphering of host-virus interactions in insects. We characterize here the pathogenesis associated with DCV infection in flies and show that it results from the tropism of the virus for an essential but poorly characterized organ in the digestive tract, the crop. Our results may have relevance for other members of the Dicistroviridae, some of which are pathogenic to beneficial or pest insect species.}, keywords = {Animals, bioinformatic, Dicistroviridae, Female, Gastrointestinal Tract, Gene Expression Profiling, hoffmann, imler, Intestinal Obstruction, M3i, meignin, Muscle, Nodaviridae, Sindbis Virus, Smooth, Viral Tropism}, pubstate = {published}, tppubtype = {article} } Drosophila C virus (DCV) is a positive-sense RNA virus belonging to the Dicistroviridae family. This natural pathogen of the model organism Drosophila melanogaster is commonly used to investigate antiviral host defense in flies, which involves both RNA interference and inducible responses. Although lethality is used routinely as a readout for the efficiency of the antiviral immune response in these studies, virus-induced pathologies in flies still are poorly understood. Here, we characterize the pathogenesis associated with systemic DCV infection. Comparison of the transcriptome of flies infected with DCV or two other positive-sense RNA viruses, Flock House virus and Sindbis virus, reveals that DCV infection, unlike those of the other two viruses, represses the expression of a large number of genes. Several of these genes are expressed specifically in the midgut and also are repressed by starvation. We show that systemic DCV infection triggers a nutritional stress in Drosophila which results from intestinal obstruction with the accumulation of peritrophic matrix at the entry of the midgut and the accumulation of the food ingested in the crop, a blind muscular food storage organ. The related virus cricket paralysis virus (CrPV), which efficiently grows in Drosophila, does not trigger this pathology. We show that DCV, but not CrPV, infects the smooth muscles surrounding the crop, causing extensive cytopathology and strongly reducing the rate of contractions. We conclude that the pathogenesis associated with systemic DCV infection results from the tropism of the virus for an important organ within the foregut of dipteran insects, the crop. IMPORTANCE: DCV is one of the few identified natural viral pathogens affecting the model organism Drosophila melanogaster. As such, it is an important virus for the deciphering of host-virus interactions in insects. We characterize here the pathogenesis associated with DCV infection in flies and show that it results from the tropism of the virus for an essential but poorly characterized organ in the digestive tract, the crop. Our results may have relevance for other members of the Dicistroviridae, some of which are pathogenic to beneficial or pest insect species. |
Bonnay, François; Nguyen, Xuan-Hung; Cohen-Berros, Eva; Troxler, Laurent; Batsche, Eric; Camonis, Jacques; Takeuchi, Osamu; Reichhart, Jean-Marc; Matt, Nicolas Akirin specifies NF-κB selectivity of Drosophila innate immune response via chromatin remodeling Article de journal EMBO J., 33 (20), p. 2349–2362, 2014, ISSN: 1460-2075. Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, Cell Cycle Proteins, Chromatin Assembly and Disassembly, chromatin remodeling, DNA-Binding Proteins, Female, Genetic, Immunity, Innate, Innate immune response, M3i, Male, matt, Mutation, NF-kappa B, NF‐κB, Promoter Regions, proteomics, reichhart, Trans-Activators, Transcription Factors, Transcriptional Activation, Two-Hybrid System Techniques @article{bonnay_akirin_2014, title = {Akirin specifies NF-κB selectivity of Drosophila innate immune response via chromatin remodeling}, author = {François Bonnay and Xuan-Hung Nguyen and Eva Cohen-Berros and Laurent Troxler and Eric Batsche and Jacques Camonis and Osamu Takeuchi and Jean-Marc Reichhart and Nicolas Matt}, doi = {10.15252/embj.201488456}, issn = {1460-2075}, year = {2014}, date = {2014-10-01}, journal = {EMBO J.}, volume = {33}, number = {20}, pages = {2349--2362}, abstract = {The network of NF-κB-dependent transcription that activates both pro- and anti-inflammatory genes in mammals is still unclear. As NF-κB factors are evolutionarily conserved, we used Drosophila to understand this network. The NF-κB transcription factor Relish activates effector gene expression following Gram-negative bacterial immune challenge. Here, we show, using a genome-wide approach, that the conserved nuclear protein Akirin is a NF-κB co-factor required for the activation of a subset of Relish-dependent genes correlating with the presence of H3K4ac epigenetic marks. A large-scale unbiased proteomic analysis revealed that Akirin orchestrates NF-κB transcriptional selectivity through the recruitment of the Osa-containing-SWI/SNF-like Brahma complex (BAP). Immune challenge in Drosophila shows that Akirin is required for the transcription of a subset of effector genes, but dispensable for the transcription of genes that are negative regulators of the innate immune response. Therefore, Akirins act as molecular selectors specifying the choice between subsets of NF-κB target genes. The discovery of this mechanism, conserved in mammals, paves the way for the establishment of more specific and less toxic anti-inflammatory drugs targeting pro-inflammatory genes.}, keywords = {Animals, bioinformatic, Cell Cycle Proteins, Chromatin Assembly and Disassembly, chromatin remodeling, DNA-Binding Proteins, Female, Genetic, Immunity, Innate, Innate immune response, M3i, Male, matt, Mutation, NF-kappa B, NF‐κB, Promoter Regions, proteomics, reichhart, Trans-Activators, Transcription Factors, Transcriptional Activation, Two-Hybrid System Techniques}, pubstate = {published}, tppubtype = {article} } The network of NF-κB-dependent transcription that activates both pro- and anti-inflammatory genes in mammals is still unclear. As NF-κB factors are evolutionarily conserved, we used Drosophila to understand this network. The NF-κB transcription factor Relish activates effector gene expression following Gram-negative bacterial immune challenge. Here, we show, using a genome-wide approach, that the conserved nuclear protein Akirin is a NF-κB co-factor required for the activation of a subset of Relish-dependent genes correlating with the presence of H3K4ac epigenetic marks. A large-scale unbiased proteomic analysis revealed that Akirin orchestrates NF-κB transcriptional selectivity through the recruitment of the Osa-containing-SWI/SNF-like Brahma complex (BAP). Immune challenge in Drosophila shows that Akirin is required for the transcription of a subset of effector genes, but dispensable for the transcription of genes that are negative regulators of the innate immune response. Therefore, Akirins act as molecular selectors specifying the choice between subsets of NF-κB target genes. The discovery of this mechanism, conserved in mammals, paves the way for the establishment of more specific and less toxic anti-inflammatory drugs targeting pro-inflammatory genes. |
Tartey, Sarang; Matsushita, Kazufumi; Vandenbon, Alexis; Ori, Daisuke; Imamura, Tomoko; Mino, Takashi; Standley, Daron M; Hoffmann, Jules A; Reichhart, Jean-Marc; Akira, Shizuo; Takeuchi, Osamu Akirin2 is critical for inducing inflammatory genes by bridging IκB-ζ and the SWI/SNF complex Article de journal EMBO J., 33 (20), p. 2332–2348, 2014, ISSN: 1460-2075. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animals, Cell Nucleus, Chromatin Assembly and Disassembly, chromatin remodeling, Chromosomal Proteins, cytokine, Cytokines, Female, Gene Expression Regulation, gene regulation, Genetic, hoffmann, Humans, Immunity, Innate, innate immunity, Knockout, Listeria monocytogenes, M3i, Macrophages, Male, Mice, Multiprotein Complexes, Non-Histone, Nuclear Proteins, Promoter Regions, Protein Binding, reichhart, Repressor Proteins, Sequence Deletion, Signal Transducing, Transcriptional Activation @article{tartey_akirin2_2014, title = {Akirin2 is critical for inducing inflammatory genes by bridging IκB-ζ and the SWI/SNF complex}, author = {Sarang Tartey and Kazufumi Matsushita and Alexis Vandenbon and Daisuke Ori and Tomoko Imamura and Takashi Mino and Daron M Standley and Jules A Hoffmann and Jean-Marc Reichhart and Shizuo Akira and Osamu Takeuchi}, doi = {10.15252/embj.201488447}, issn = {1460-2075}, year = {2014}, date = {2014-10-01}, journal = {EMBO J.}, volume = {33}, number = {20}, pages = {2332--2348}, abstract = {Transcription of inflammatory genes in innate immune cells is coordinately regulated by transcription factors, including NF-κB, and chromatin modifiers. However, it remains unclear how microbial sensing initiates chromatin remodeling. Here, we show that Akirin2, an evolutionarily conserved nuclear protein, bridges NF-κB and the chromatin remodeling SWI/SNF complex by interacting with BRG1-Associated Factor 60 (BAF60) proteins as well as IκB-ζ, which forms a complex with the NF-κB p50 subunit. These interactions are essential for Toll-like receptor-, RIG-I-, and Listeria-mediated expression of proinflammatory genes including Il6 and Il12b in macrophages. Consistently, effective clearance of Listeria infection required Akirin2. Furthermore, Akirin2 and IκB-ζ recruitment to the Il6 promoter depend upon the presence of IκB-ζ and Akirin2, respectively, for regulation of chromatin remodeling. BAF60 proteins were also essential for the induction of Il6 in response to LPS stimulation. Collectively, the IκB-ζ-Akirin2-BAF60 complex physically links the NF-κB and SWI/SNF complexes in innate immune cell activation. By recruiting SWI/SNF chromatin remodellers to IκB-ζ, transcriptional coactivator for NF-κB, the conserved nuclear protein Akirin2 stimulates pro-inflammatory gene promoters in mouse macrophages during innate immune responses to viral or bacterial infection.}, keywords = {Adaptor Proteins, Animals, Cell Nucleus, Chromatin Assembly and Disassembly, chromatin remodeling, Chromosomal Proteins, cytokine, Cytokines, Female, Gene Expression Regulation, gene regulation, Genetic, hoffmann, Humans, Immunity, Innate, innate immunity, Knockout, Listeria monocytogenes, M3i, Macrophages, Male, Mice, Multiprotein Complexes, Non-Histone, Nuclear Proteins, Promoter Regions, Protein Binding, reichhart, Repressor Proteins, Sequence Deletion, Signal Transducing, Transcriptional Activation}, pubstate = {published}, tppubtype = {article} } Transcription of inflammatory genes in innate immune cells is coordinately regulated by transcription factors, including NF-κB, and chromatin modifiers. However, it remains unclear how microbial sensing initiates chromatin remodeling. Here, we show that Akirin2, an evolutionarily conserved nuclear protein, bridges NF-κB and the chromatin remodeling SWI/SNF complex by interacting with BRG1-Associated Factor 60 (BAF60) proteins as well as IκB-ζ, which forms a complex with the NF-κB p50 subunit. These interactions are essential for Toll-like receptor-, RIG-I-, and Listeria-mediated expression of proinflammatory genes including Il6 and Il12b in macrophages. Consistently, effective clearance of Listeria infection required Akirin2. Furthermore, Akirin2 and IκB-ζ recruitment to the Il6 promoter depend upon the presence of IκB-ζ and Akirin2, respectively, for regulation of chromatin remodeling. BAF60 proteins were also essential for the induction of Il6 in response to LPS stimulation. Collectively, the IκB-ζ-Akirin2-BAF60 complex physically links the NF-κB and SWI/SNF complexes in innate immune cell activation. By recruiting SWI/SNF chromatin remodellers to IκB-ζ, transcriptional coactivator for NF-κB, the conserved nuclear protein Akirin2 stimulates pro-inflammatory gene promoters in mouse macrophages during innate immune responses to viral or bacterial infection. |
Amcheslavsky, Alla; Song, Wei; Li, Qi; Nie, Yingchao; Bragatto, Ivan; Ferrandon, Dominique; Perrimon, Norbert; Ip, Tony Y Enteroendocrine cells support intestinal stem-cell-mediated homeostasis in Drosophila Article de journal Cell Rep, 9 (1), p. 32–39, 2014, ISSN: 2211-1247. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Differentiation, Enterocytes, Enteroendocrine Cells, Female, ferrandon, Homeostasis, Intestines, M3i, Male, Stem Cells, Tachykinins @article{amcheslavsky_enteroendocrine_2014b, title = {Enteroendocrine cells support intestinal stem-cell-mediated homeostasis in Drosophila}, author = {Alla Amcheslavsky and Wei Song and Qi Li and Yingchao Nie and Ivan Bragatto and Dominique Ferrandon and Norbert Perrimon and Tony Y Ip}, doi = {10.1016/j.celrep.2014.08.052}, issn = {2211-1247}, year = {2014}, date = {2014-10-01}, journal = {Cell Rep}, volume = {9}, number = {1}, pages = {32--39}, abstract = {Intestinal stem cells in the adult Drosophila midgut are regulated by growth factors produced from the surrounding niche cells including enterocytes and visceral muscle. The role of the other major cell type, the secretory enteroendocrine cells, in regulating intestinal stem cells remains unclear. We show here that newly eclosed scute loss-of-function mutant flies are completely devoid of enteroendocrine cells. These enteroendocrine cell-less flies have normal ingestion and fecundity but shorter lifespan. Moreover, in these newly eclosed mutant flies, the diet-stimulated midgut growth that depends on the insulin-like peptide 3 expression in the surrounding muscle is defective. The depletion of Tachykinin-producing enteroendocrine cells or knockdown of Tachykinin leads to a similar although less severe phenotype. These results establish that enteroendocrine cells serve as an important link between diet and visceral muscle expression of an insulin-like growth factor to stimulate intestinal stem cell proliferation and tissue growth.}, keywords = {Animals, Cell Differentiation, Enterocytes, Enteroendocrine Cells, Female, ferrandon, Homeostasis, Intestines, M3i, Male, Stem Cells, Tachykinins}, pubstate = {published}, tppubtype = {article} } Intestinal stem cells in the adult Drosophila midgut are regulated by growth factors produced from the surrounding niche cells including enterocytes and visceral muscle. The role of the other major cell type, the secretory enteroendocrine cells, in regulating intestinal stem cells remains unclear. We show here that newly eclosed scute loss-of-function mutant flies are completely devoid of enteroendocrine cells. These enteroendocrine cell-less flies have normal ingestion and fecundity but shorter lifespan. Moreover, in these newly eclosed mutant flies, the diet-stimulated midgut growth that depends on the insulin-like peptide 3 expression in the surrounding muscle is defective. The depletion of Tachykinin-producing enteroendocrine cells or knockdown of Tachykinin leads to a similar although less severe phenotype. These results establish that enteroendocrine cells serve as an important link between diet and visceral muscle expression of an insulin-like growth factor to stimulate intestinal stem cell proliferation and tissue growth. |
Lamiable, Olivier; Imler, Jean-Luc Induced antiviral innate immunity in Drosophila Article de journal Current Opinion in Microbiology, 20 , p. 62–68, 2014, ISSN: 1879-0364. Résumé | Liens | BibTeX | Étiquettes: Animals, Gene Expression Regulation, Host-Pathogen Interactions, imler, Immunity, Innate, M3i, RNA Viruses, Signal Transduction @article{lamiable_induced_2014, title = {Induced antiviral innate immunity in Drosophila}, author = {Olivier Lamiable and Jean-Luc Imler}, doi = {10.1016/j.mib.2014.05.006}, issn = {1879-0364}, year = {2014}, date = {2014-08-01}, journal = {Current Opinion in Microbiology}, volume = {20}, pages = {62--68}, abstract = {Immunity to viral infections in the model organism Drosophila melanogaster involves both RNA interference and additional induced responses. The latter include not only cellular mechanisms such as programmed cell death and autophagy, but also the induction of a large set of genes, some of which contribute to the control of viral replication and resistance to infection. This induced response to infection is complex and involves both virus-specific and cell-type specific mechanisms. We review here recent developments, from the sensing of viral infection to the induction of signaling pathways and production of antiviral effector molecules. Our current understanding, although still partial, validates the Drosophila model of antiviral induced immunity for insect pests and disease vectors, as well as for mammals.}, keywords = {Animals, Gene Expression Regulation, Host-Pathogen Interactions, imler, Immunity, Innate, M3i, RNA Viruses, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Immunity to viral infections in the model organism Drosophila melanogaster involves both RNA interference and additional induced responses. The latter include not only cellular mechanisms such as programmed cell death and autophagy, but also the induction of a large set of genes, some of which contribute to the control of viral replication and resistance to infection. This induced response to infection is complex and involves both virus-specific and cell-type specific mechanisms. We review here recent developments, from the sensing of viral infection to the induction of signaling pathways and production of antiviral effector molecules. Our current understanding, although still partial, validates the Drosophila model of antiviral induced immunity for insect pests and disease vectors, as well as for mammals. |
Goto, Akira; Fukuyama, Hidehiro; Imler, Jean-Luc; Hoffmann, Jules A The chromatin regulator DMAP1 modulates activity of the nuclear factor B (NF-B) transcription factor Relish in the Drosophila innate immune response Article de journal The Journal of Biological Chemistry, 289 (30), p. 20470–20476, 2014, ISSN: 1083-351X. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Line, Chromatin Assembly and Disassembly, Epistasis, Escherichia coli, Escherichia coli Infections, Genetic, hoffmann, imler, Immunity, Innate, M3i, NF-kappa B, Repressor Proteins, Signal Transduction, Transcription Factors @article{goto_chromatin_2014, title = {The chromatin regulator DMAP1 modulates activity of the nuclear factor B (NF-B) transcription factor Relish in the Drosophila innate immune response}, author = {Akira Goto and Hidehiro Fukuyama and Jean-Luc Imler and Jules A Hoffmann}, doi = {10.1074/jbc.C114.553719}, issn = {1083-351X}, year = {2014}, date = {2014-07-01}, journal = {The Journal of Biological Chemistry}, volume = {289}, number = {30}, pages = {20470--20476}, abstract = {The host defense of the model organism Drosophila is under the control of two major signaling cascades controlling transcription factors of the NF-B family, the Toll and the immune deficiency (IMD) pathways. The latter shares extensive similarities with the mammalian TNF-R pathway and was initially discovered for its role in anti-Gram-negative bacterial reactions. A previous interactome study from this laboratory reported that an unexpectedly large number of proteins are binding to the canonical components of the IMD pathway. Here, we focus on DNA methyltransferase-associated protein 1 (DMAP1), which this study identified as an interactant of Relish, a Drosophila transcription factor reminiscent of the mammalian p105 NF-B protein. We show that silencing of DMAP1 expression both in S2 cells and in flies results in a significant reduction of Escherichia coli-induced expression of antimicrobial peptides. Epistatic analysis indicates that DMAP1 acts in parallel or downstream of Relish. Co-immunoprecipitation experiments further reveal that, in addition to Relish, DMAP1 also interacts with Akirin and the Brahma-associated protein 55 kDa (BAP55). Taken together, these results reveal that DMAP1 is a novel nuclear modulator of the IMD pathway, possibly acting at the level of chromatin remodeling.}, keywords = {Animals, Cell Line, Chromatin Assembly and Disassembly, Epistasis, Escherichia coli, Escherichia coli Infections, Genetic, hoffmann, imler, Immunity, Innate, M3i, NF-kappa B, Repressor Proteins, Signal Transduction, Transcription Factors}, pubstate = {published}, tppubtype = {article} } The host defense of the model organism Drosophila is under the control of two major signaling cascades controlling transcription factors of the NF-B family, the Toll and the immune deficiency (IMD) pathways. The latter shares extensive similarities with the mammalian TNF-R pathway and was initially discovered for its role in anti-Gram-negative bacterial reactions. A previous interactome study from this laboratory reported that an unexpectedly large number of proteins are binding to the canonical components of the IMD pathway. Here, we focus on DNA methyltransferase-associated protein 1 (DMAP1), which this study identified as an interactant of Relish, a Drosophila transcription factor reminiscent of the mammalian p105 NF-B protein. We show that silencing of DMAP1 expression both in S2 cells and in flies results in a significant reduction of Escherichia coli-induced expression of antimicrobial peptides. Epistatic analysis indicates that DMAP1 acts in parallel or downstream of Relish. Co-immunoprecipitation experiments further reveal that, in addition to Relish, DMAP1 also interacts with Akirin and the Brahma-associated protein 55 kDa (BAP55). Taken together, these results reveal that DMAP1 is a novel nuclear modulator of the IMD pathway, possibly acting at the level of chromatin remodeling. |
Imler, Jean-Luc Overview of Drosophila immunity: a historical perspective Article de journal Developmental and Comparative Immunology, 42 (1), p. 3–15, 2014, ISSN: 1879-0089. Résumé | Liens | BibTeX | Étiquettes: Allergy and Immunology, Animal, Animals, Antimicrobial Cationic Peptides, Antimicrobial peptides, history, Humans, IMD pathway, imler, Immunity, Innate, innate immunity, M3i, Models, Pattern recognition receptors, Signal Transduction, Toll-Like Receptors @article{imler_overview_2014, title = {Overview of Drosophila immunity: a historical perspective}, author = {Jean-Luc Imler}, doi = {10.1016/j.dci.2013.08.018}, issn = {1879-0089}, year = {2014}, date = {2014-01-01}, journal = {Developmental and Comparative Immunology}, volume = {42}, number = {1}, pages = {3--15}, abstract = {The functional analysis of genes from the model organism Drosophila melanogaster has provided invaluable information for many cellular and developmental or physiological processes, including immunity. The best-understood aspect of Drosophila immunity is the inducible humoral response, first recognized in 1972. This pioneering work led to a remarkable series of findings over the next 30 years, ranging from the identification and characterization of the antimicrobial peptides produced, to the deciphering of the signalling pathways activating the genes that encode them and, ultimately, to the discovery of the receptors sensing infection. These studies on an insect model coincided with a revival of the field of innate immunity, and had an unanticipated impact on the biomedical field.}, keywords = {Allergy and Immunology, Animal, Animals, Antimicrobial Cationic Peptides, Antimicrobial peptides, history, Humans, IMD pathway, imler, Immunity, Innate, innate immunity, M3i, Models, Pattern recognition receptors, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The functional analysis of genes from the model organism Drosophila melanogaster has provided invaluable information for many cellular and developmental or physiological processes, including immunity. The best-understood aspect of Drosophila immunity is the inducible humoral response, first recognized in 1972. This pioneering work led to a remarkable series of findings over the next 30 years, ranging from the identification and characterization of the antimicrobial peptides produced, to the deciphering of the signalling pathways activating the genes that encode them and, ultimately, to the discovery of the receptors sensing infection. These studies on an insect model coincided with a revival of the field of innate immunity, and had an unanticipated impact on the biomedical field. |
Haller, Samantha; Limmer, Stefanie; Ferrandon, Dominique Assessing Pseudomonas virulence with a nonmammalian host: Drosophila melanogaster Article de journal Methods Mol. Biol., 1149 , p. 723–740, 2014, ISSN: 1940-6029. Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Antimicrobial Cationic Peptides, Biological Assay, Colony Count, Disease Models, ferrandon, Hemolymph, Host-Pathogen Interactions, M3i, Mammals, Microbial, Pseudomonas aeruginosa, Pseudomonas Infections, Reverse Transcriptase Polymerase Chain Reaction, Virulence @article{haller_assessing_2014b, title = {Assessing Pseudomonas virulence with a nonmammalian host: Drosophila melanogaster}, author = {Samantha Haller and Stefanie Limmer and Dominique Ferrandon}, doi = {10.1007/978-1-4939-0473-0_56}, issn = {1940-6029}, year = {2014}, date = {2014-01-01}, journal = {Methods Mol. Biol.}, volume = {1149}, pages = {723--740}, abstract = {Drosophila melanogaster flies represent an interesting model to study host-pathogen interactions as: (1) they are cheap and easy to raise rapidly and do not bring up ethical issues, (2) available genetic tools are highly sophisticated, for instance allowing tissue-specific alteration of gene expression, e.g., of immune genes, (3) they have a relatively complex organization, with distinct digestive tract and body cavity in which local or systemic infections, respectively, take place, (4) a medium throughput can be achieved in genetic screens, for instance looking for Pseudomonas aeruginosa mutants with altered virulence. We present here the techniques used to investigate host-pathogen relationships, namely the two major models of infections as well as the relevant parameters used to monitor the infection (survival, bacterial titer, induction of host immune response).}, keywords = {Animal, Animals, Antimicrobial Cationic Peptides, Biological Assay, Colony Count, Disease Models, ferrandon, Hemolymph, Host-Pathogen Interactions, M3i, Mammals, Microbial, Pseudomonas aeruginosa, Pseudomonas Infections, Reverse Transcriptase Polymerase Chain Reaction, Virulence}, pubstate = {published}, tppubtype = {article} } Drosophila melanogaster flies represent an interesting model to study host-pathogen interactions as: (1) they are cheap and easy to raise rapidly and do not bring up ethical issues, (2) available genetic tools are highly sophisticated, for instance allowing tissue-specific alteration of gene expression, e.g., of immune genes, (3) they have a relatively complex organization, with distinct digestive tract and body cavity in which local or systemic infections, respectively, take place, (4) a medium throughput can be achieved in genetic screens, for instance looking for Pseudomonas aeruginosa mutants with altered virulence. We present here the techniques used to investigate host-pathogen relationships, namely the two major models of infections as well as the relevant parameters used to monitor the infection (survival, bacterial titer, induction of host immune response). |
Lestradet, Matthieu; Lee, Kwan Zin; Ferrandon, Dominique Drosophila as a model for intestinal infections Article de journal Methods Mol Biol, 1197 , p. 11–40, 2014, ISSN: 1940-6029 (Electronic) 1064-3745 (Linking). Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Bacterial Physiological Phenomena, Disease Models, ferrandon, Gastrointestinal Tract, Host-Pathogen Interactions, M3i @article{lestradet_drosophila_2014b, title = {Drosophila as a model for intestinal infections}, author = {Matthieu Lestradet and Kwan Zin Lee and Dominique Ferrandon}, doi = {10.1007/978-1-4939-1261-2_2}, issn = {1940-6029 (Electronic) 1064-3745 (Linking)}, year = {2014}, date = {2014-01-01}, journal = {Methods Mol Biol}, volume = {1197}, pages = {11--40}, abstract = {Drosophila melanogaster is a powerful model to study infections thanks to the power of its genetics and knowledge on its biology accumulated for over a century. While the systemic humoral immune response against invading microbes has been intensively studied in the past two decades, the study of intestinal infections is more recent. Here, we present the methods that are currently in use to probe various aspects of the host-pathogen interactions between Drosophila and ingested microbes, with an emphasis on the study of the midgut epithelium, which constitutes the major interface between the organism and the microbe-rich ingested food.}, keywords = {Animal, Animals, Bacterial Physiological Phenomena, Disease Models, ferrandon, Gastrointestinal Tract, Host-Pathogen Interactions, M3i}, pubstate = {published}, tppubtype = {article} } Drosophila melanogaster is a powerful model to study infections thanks to the power of its genetics and knowledge on its biology accumulated for over a century. While the systemic humoral immune response against invading microbes has been intensively studied in the past two decades, the study of intestinal infections is more recent. Here, we present the methods that are currently in use to probe various aspects of the host-pathogen interactions between Drosophila and ingested microbes, with an emphasis on the study of the midgut epithelium, which constitutes the major interface between the organism and the microbe-rich ingested food. |
2013 |
Petrillo, Jessica E; Venter, Arno P; Short, James R; Gopal, Radhika; Deddouche, Safia; Lamiable, Olivier; Imler, Jean-Luc; Schneemann, Anette Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2 Article de journal Journal of Virology, 87 (24), p. 13409–13421, 2013, ISSN: 1098-5514. Résumé | Liens | BibTeX | Étiquettes: Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins @article{petrillo_cytoplasmic_2013, title = {Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2}, author = {Jessica E Petrillo and Arno P Venter and James R Short and Radhika Gopal and Safia Deddouche and Olivier Lamiable and Jean-Luc Imler and Anette Schneemann}, doi = {10.1128/JVI.02362-13}, issn = {1098-5514}, year = {2013}, date = {2013-12-01}, journal = {Journal of Virology}, volume = {87}, number = {24}, pages = {13409--13421}, abstract = {Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle.}, keywords = {Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins}, pubstate = {published}, tppubtype = {article} } Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle. |
Fukuyama, Hidehiro; Verdier, Yann; Guan, Yongsheng; Makino-Okamura, Chieko; Shilova, Victoria; Liu, Xi; Maksoud, Elie; Matsubayashi, Jun; Haddad, Iman; Spirohn, Kerstin; Ono, Kenichiro; Hetru, Charles; Rossier, Jean; Ideker, Trey; Boutros, Michael; Vinh, Joëlle; Hoffmann, Jules A Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge Article de journal Proc. Natl. Acad. Sci. U.S.A., 110 (26), p. 10717–10722, 2013, ISSN: 1091-6490. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Chromatin Assembly and Disassembly, Escherichia coli, functional proteomics, Genes, Genetically Modified, Histone Acetyltransferases, hoffmann, Host-Pathogen Interactions, Humans, IMD interactome, Insect, M3i, Models, Molecular, Protein Interaction Maps, Sequence Homology, Signal Transduction, small ubiquitin-like modifier @article{fukuyama_landscape_2013, title = {Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge}, author = {Hidehiro Fukuyama and Yann Verdier and Yongsheng Guan and Chieko Makino-Okamura and Victoria Shilova and Xi Liu and Elie Maksoud and Jun Matsubayashi and Iman Haddad and Kerstin Spirohn and Kenichiro Ono and Charles Hetru and Jean Rossier and Trey Ideker and Michael Boutros and Joëlle Vinh and Jules A Hoffmann}, doi = {10.1073/pnas.1304380110}, issn = {1091-6490}, year = {2013}, date = {2013-06-01}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, volume = {110}, number = {26}, pages = {10717--10722}, abstract = {The Drosophila defense against pathogens largely relies on the activation of two signaling pathways: immune deficiency (IMD) and Toll. The IMD pathway is triggered mainly by Gram-negative bacteria, whereas the Toll pathway responds predominantly to Gram-positive bacteria and fungi. The activation of these pathways leads to the rapid induction of numerous NF-κB-induced immune response genes, including antimicrobial peptide genes. The IMD pathway shows significant similarities with the TNF receptor pathway. Recent evidence indicates that the IMD pathway is also activated in response to various noninfectious stimuli (i.e., inflammatory-like reactions). To gain a better understanding of the molecular machinery underlying the pleiotropic functions of this pathway, we first performed a comprehensive proteomics analysis to identify the proteins interacting with the 11 canonical members of the pathway initially identified by genetic studies. We identified 369 interacting proteins (corresponding to 291 genes) in heat-killed Escherichia coli-stimulated Drosophila S2 cells, 92% of which have human orthologs. A comparative analysis of gene ontology from fly or human gene annotation databases points to four significant common categories: (i) the NuA4, nucleosome acetyltransferase of H4, histone acetyltransferase complex, (ii) the switching defective/sucrose nonfermenting-type chromatin remodeling complex, (iii) transcription coactivator activity, and (iv) translation factor activity. Here we demonstrate that sumoylation of the IκB kinase homolog immune response-deficient 5 plays an important role in the induction of antimicrobial peptide genes through a highly conserved sumoylation consensus site during bacterial challenge. Taken together, the proteomics data presented here provide a unique avenue for a comparative functional analysis of proteins involved in innate immune reactions in flies and mammals.}, keywords = {Amino Acid, Animals, Chromatin Assembly and Disassembly, Escherichia coli, functional proteomics, Genes, Genetically Modified, Histone Acetyltransferases, hoffmann, Host-Pathogen Interactions, Humans, IMD interactome, Insect, M3i, Models, Molecular, Protein Interaction Maps, Sequence Homology, Signal Transduction, small ubiquitin-like modifier}, pubstate = {published}, tppubtype = {article} } The Drosophila defense against pathogens largely relies on the activation of two signaling pathways: immune deficiency (IMD) and Toll. The IMD pathway is triggered mainly by Gram-negative bacteria, whereas the Toll pathway responds predominantly to Gram-positive bacteria and fungi. The activation of these pathways leads to the rapid induction of numerous NF-κB-induced immune response genes, including antimicrobial peptide genes. The IMD pathway shows significant similarities with the TNF receptor pathway. Recent evidence indicates that the IMD pathway is also activated in response to various noninfectious stimuli (i.e., inflammatory-like reactions). To gain a better understanding of the molecular machinery underlying the pleiotropic functions of this pathway, we first performed a comprehensive proteomics analysis to identify the proteins interacting with the 11 canonical members of the pathway initially identified by genetic studies. We identified 369 interacting proteins (corresponding to 291 genes) in heat-killed Escherichia coli-stimulated Drosophila S2 cells, 92% of which have human orthologs. A comparative analysis of gene ontology from fly or human gene annotation databases points to four significant common categories: (i) the NuA4, nucleosome acetyltransferase of H4, histone acetyltransferase complex, (ii) the switching defective/sucrose nonfermenting-type chromatin remodeling complex, (iii) transcription coactivator activity, and (iv) translation factor activity. Here we demonstrate that sumoylation of the IκB kinase homolog immune response-deficient 5 plays an important role in the induction of antimicrobial peptide genes through a highly conserved sumoylation consensus site during bacterial challenge. Taken together, the proteomics data presented here provide a unique avenue for a comparative functional analysis of proteins involved in innate immune reactions in flies and mammals. |
Kobayashi, Taira; Ogawa, Michinaga; Sanada, Takahito; Mimuro, Hitomi; Kim, Minsoo; Ashida, Hiroshi; Akakura, Reiko; Yoshida, Mitsutaka; Kawalec, Magdalena; Reichhart, Jean-Marc; Mizushima, Tsunehiro; Sasakawa, Chihiro The Shigella OspC3 effector inhibits caspase-4, antagonizes inflammatory cell death, and promotes epithelial infection Article de journal Cell Host Microbe, 13 (5), p. 570–583, 2013, ISSN: 1934-6069. Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Bacillary, Bacterial, Bacterial Proteins, Caspases, Cell Death, Cell Line, Disease Models, DNA, Dysentery, Enzyme Inhibitors, Epithelial Cells, Escherichia coli, Gene Knockout Techniques, Guinea Pigs, Host-Pathogen Interactions, Humans, Initiator, M3i, Protein Binding, Protein Interaction Mapping, reichhart, Salmonella typhimurium, Sequence Analysis, Shigella flexneri, Virulence Factors @article{kobayashi_shigella_2013, title = {The Shigella OspC3 effector inhibits caspase-4, antagonizes inflammatory cell death, and promotes epithelial infection}, author = {Taira Kobayashi and Michinaga Ogawa and Takahito Sanada and Hitomi Mimuro and Minsoo Kim and Hiroshi Ashida and Reiko Akakura and Mitsutaka Yoshida and Magdalena Kawalec and Jean-Marc Reichhart and Tsunehiro Mizushima and Chihiro Sasakawa}, doi = {10.1016/j.chom.2013.04.012}, issn = {1934-6069}, year = {2013}, date = {2013-05-01}, journal = {Cell Host Microbe}, volume = {13}, number = {5}, pages = {570--583}, abstract = {Caspase-mediated inflammatory cell death acts as an intrinsic defense mechanism against infection. Bacterial pathogens deploy countermeasures against inflammatory cell death, but the mechanisms by which they do this remain largely unclear. In a screen for Shigella flexneri effectors that regulate cell death during infection, we discovered that Shigella infection induced acute inflammatory, caspase-4-dependent epithelial cell death, which is counteracted by the bacterial OspC3 effector. OspC3 interacts with the caspase-4-p19 subunit and inhibits its activation by preventing caspase-4-p19 and caspase-4-p10 heterodimerization by depositing the conserved OspC3 X1-Y-X₂-D-X₃ motif at the putative catalytic pocket of caspase-4. Infection of guinea pigs with a Shigella ospC3-deficient mutant resulted in enhanced inflammatory cell death and associated symptoms, correlating with decreased bacterial burdens. Salmonella Typhimurium and enteropathogenic Escherichia coli infection also induced caspase-4-dependent epithelial death. These findings highlight the importance of caspase-4-dependent innate immune responses and demonstrate that Shigella delivers a caspase-4-specific inhibitor to delay epithelial cell death and promote infection.}, keywords = {Animal, Animals, Bacillary, Bacterial, Bacterial Proteins, Caspases, Cell Death, Cell Line, Disease Models, DNA, Dysentery, Enzyme Inhibitors, Epithelial Cells, Escherichia coli, Gene Knockout Techniques, Guinea Pigs, Host-Pathogen Interactions, Humans, Initiator, M3i, Protein Binding, Protein Interaction Mapping, reichhart, Salmonella typhimurium, Sequence Analysis, Shigella flexneri, Virulence Factors}, pubstate = {published}, tppubtype = {article} } Caspase-mediated inflammatory cell death acts as an intrinsic defense mechanism against infection. Bacterial pathogens deploy countermeasures against inflammatory cell death, but the mechanisms by which they do this remain largely unclear. In a screen for Shigella flexneri effectors that regulate cell death during infection, we discovered that Shigella infection induced acute inflammatory, caspase-4-dependent epithelial cell death, which is counteracted by the bacterial OspC3 effector. OspC3 interacts with the caspase-4-p19 subunit and inhibits its activation by preventing caspase-4-p19 and caspase-4-p10 heterodimerization by depositing the conserved OspC3 X1-Y-X₂-D-X₃ motif at the putative catalytic pocket of caspase-4. Infection of guinea pigs with a Shigella ospC3-deficient mutant resulted in enhanced inflammatory cell death and associated symptoms, correlating with decreased bacterial burdens. Salmonella Typhimurium and enteropathogenic Escherichia coli infection also induced caspase-4-dependent epithelial death. These findings highlight the importance of caspase-4-dependent innate immune responses and demonstrate that Shigella delivers a caspase-4-specific inhibitor to delay epithelial cell death and promote infection. |
Quintin, Jessica; Asmar, Joelle; Matskevich, Alexey A; Lafarge, Marie-Céline; Ferrandon, Dominique The Drosophila Toll pathway controls but does not clear Candida glabrata infections Article de journal J. Immunol., 190 (6), p. 2818–2827, 2013, ISSN: 1550-6606. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence @article{quintin_drosophila_2013b, title = {The Drosophila Toll pathway controls but does not clear Candida glabrata infections}, author = {Jessica Quintin and Joelle Asmar and Alexey A Matskevich and Marie-Céline Lafarge and Dominique Ferrandon}, doi = {10.4049/jimmunol.1201861}, issn = {1550-6606}, year = {2013}, date = {2013-03-01}, journal = {J. Immunol.}, volume = {190}, number = {6}, pages = {2818--2827}, abstract = {The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host.}, keywords = {Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence}, pubstate = {published}, tppubtype = {article} } The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host. |
Bonnay, François; Cohen-Berros, Eva; Hoffmann, Martine; Kim, Sabrina Y; Boulianne, Gabrielle L; Hoffmann, Jules A; Matt, Nicolas; Reichhart, Jean-Marc Big bang gene modulates gut immune tolerance in Drosophila Article de journal Proc. Natl. Acad. Sci. U.S.A., 110 (8), p. 2957–2962, 2013, ISSN: 1091-6490. Résumé | Liens | BibTeX | Étiquettes: Animals, hoffmann, Immune Tolerance, Longevity, M3i, matt, Membrane Proteins, reichhart @article{bonnay_big_2013, title = {Big bang gene modulates gut immune tolerance in Drosophila}, author = {François Bonnay and Eva Cohen-Berros and Martine Hoffmann and Sabrina Y Kim and Gabrielle L Boulianne and Jules A Hoffmann and Nicolas Matt and Jean-Marc Reichhart}, doi = {10.1073/pnas.1221910110}, issn = {1091-6490}, year = {2013}, date = {2013-02-01}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, volume = {110}, number = {8}, pages = {2957--2962}, abstract = {Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases.}, keywords = {Animals, hoffmann, Immune Tolerance, Longevity, M3i, matt, Membrane Proteins, reichhart}, pubstate = {published}, tppubtype = {article} } Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases. |
Ferrandon, Dominique The complementary facets of epithelial host defenses in the genetic model organism Drosophila melanogaster: from resistance to resilience Article de journal Curr. Opin. Immunol., 25 (1), p. 59–70, 2013, ISSN: 1879-0372. Résumé | Liens | BibTeX | Étiquettes: Adult Stem Cells, aging, Animal, Animals, Cell Proliferation, Disease Models, Enterocytes, ferrandon, Humans, Immunity, Intestinal Mucosa, M3i, Metagenome, Stem Cell Niche, Wound Healing @article{ferrandon_complementary_2013b, title = {The complementary facets of epithelial host defenses in the genetic model organism Drosophila melanogaster: from resistance to resilience}, author = {Dominique Ferrandon}, doi = {10.1016/j.coi.2012.11.008}, issn = {1879-0372}, year = {2013}, date = {2013-02-01}, journal = {Curr. Opin. Immunol.}, volume = {25}, number = {1}, pages = {59--70}, abstract = {Significant advances have been made in our understanding of the host defense against microbial infections taking place at frontier epithelia of Drosophila flies. Immune deficiency (IMD), the major NF-κB immune response pathway induced in these epithelia, displays remarkable adaptations in its activation and regulation in the respiratory and digestive tract. The host defense against ingested pathogens is not limited to resistance, that is, the immune response. It also involves resilience, the capacity of the host to endure and repair damages inflicted by pathogens or the host's own immune response. For instance, enterocytes damaged by pathogens, the microbiota of aging flies, or host-derived reactive oxygen species (ROS), are replaced under the control of multiple pathways by the compensatory proliferation of intestinal stem cells (ISCs).}, keywords = {Adult Stem Cells, aging, Animal, Animals, Cell Proliferation, Disease Models, Enterocytes, ferrandon, Humans, Immunity, Intestinal Mucosa, M3i, Metagenome, Stem Cell Niche, Wound Healing}, pubstate = {published}, tppubtype = {article} } Significant advances have been made in our understanding of the host defense against microbial infections taking place at frontier epithelia of Drosophila flies. Immune deficiency (IMD), the major NF-κB immune response pathway induced in these epithelia, displays remarkable adaptations in its activation and regulation in the respiratory and digestive tract. The host defense against ingested pathogens is not limited to resistance, that is, the immune response. It also involves resilience, the capacity of the host to endure and repair damages inflicted by pathogens or the host's own immune response. For instance, enterocytes damaged by pathogens, the microbiota of aging flies, or host-derived reactive oxygen species (ROS), are replaced under the control of multiple pathways by the compensatory proliferation of intestinal stem cells (ISCs). |
Baron, Olga Lucia; van West, Pieter; Industri, Benoit; Ponchet, Michel; Dubreuil, Géraldine; Gourbal, Benjamin; Reichhart, Jean-Marc; Coustau, Christine Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections Article de journal PLoS Pathog., 9 (12), p. e1003792, 2013, ISSN: 1553-7374. Résumé | Liens | BibTeX | Étiquettes: Acute-Phase Proteins, Animals, Antimicrobial Cationic Peptides, Biomphalaria, Blood Proteins, Carrier Proteins, Cell Membrane, Cell Membrane Permeability, Cloning, Escherichia coli, Female, Immunity, infection, M3i, Maternally-Acquired, Membrane Glycoproteins, Microbial Sensitivity Tests, Molecular, Oomycetes, Recombinant Proteins, reichhart, Zygote @article{baron_parental_2013, title = {Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections}, author = {Olga Lucia Baron and Pieter van West and Benoit Industri and Michel Ponchet and Géraldine Dubreuil and Benjamin Gourbal and Jean-Marc Reichhart and Christine Coustau}, doi = {10.1371/journal.ppat.1003792}, issn = {1553-7374}, year = {2013}, date = {2013-01-01}, journal = {PLoS Pathog.}, volume = {9}, number = {12}, pages = {e1003792}, abstract = {Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members.}, keywords = {Acute-Phase Proteins, Animals, Antimicrobial Cationic Peptides, Biomphalaria, Blood Proteins, Carrier Proteins, Cell Membrane, Cell Membrane Permeability, Cloning, Escherichia coli, Female, Immunity, infection, M3i, Maternally-Acquired, Membrane Glycoproteins, Microbial Sensitivity Tests, Molecular, Oomycetes, Recombinant Proteins, reichhart, Zygote}, pubstate = {published}, tppubtype = {article} } Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members. |
Ayyaz, Arshad; Giammarinaro, Philippe; Liégeois, Samuel; Lestradet, Matthieu; Ferrandon, Dominique Immunobiology, 218 (4), p. 635–644, 2013, ISSN: 1878-3279. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Differentiation, Disease Models, ferrandon, Immunity, Immunologic, Innate, Intestinal Diseases, M3i, Mucosal, Mutation, Receptors, Signal Transducing, Staphylococcal Infections, Staphylococcus, Starvation, Toll-Like Receptors @article{ayyaz_negative_2013b, title = {A negative role for MyD88 in the resistance to starvation as revealed in an intestinal infection of Drosophila melanogaster with the Gram-positive bacterium Staphylococcus xylosus}, author = {Arshad Ayyaz and Philippe Giammarinaro and Samuel Liégeois and Matthieu Lestradet and Dominique Ferrandon}, doi = {10.1016/j.imbio.2012.07.027}, issn = {1878-3279}, year = {2013}, date = {2013-01-01}, journal = {Immunobiology}, volume = {218}, number = {4}, pages = {635--644}, abstract = {Drosophila melanogaster is a useful model to investigate mucosal immunity. The immune response to intestinal infections is mediated partly by the Immune deficiency (IMD) pathway, which only gets activated by a type of peptidoglycan lacking in several medically important Gram-positive bacterial species such as Staphylococcus. Thus, the intestinal host defense against such bacterial strains remains poorly known. Here, we have used Staphylococcus xylosus to develop a model of intestinal infections by Gram-positive bacteria. S. xylosus behaves as an opportunistic pathogen in a septic injury model, being able to kill only flies immunodeficient either for the Toll pathway or the cellular response. When ingested, it is controlled by IMD-independent host intestinal defenses, yet flies eventually die. Having excluded an overreaction of the immune response and the action of toxins, we find that flies actually succumb to starvation, likely as a result of a competition for sucrose between the bacteria and the flies. Fat stores of wild-type flies are severely reduced within a day, a period when sucrose is not yet exhausted in the feeding solution. Interestingly, the Toll pathway mutant MyD88 is more resistant to the ingestion of S. xylosus and to starvation than wild-type flies. MyD88 flies do not rapidly deplete their fat stores when starved, in contrast to wild-type flies. Thus, we have uncovered a novel function of MyD88 in the regulation of metabolism that appears to be independent of its known roles in immunity and development.}, keywords = {Adaptor Proteins, Animal, Animals, Antigens, Differentiation, Disease Models, ferrandon, Immunity, Immunologic, Innate, Intestinal Diseases, M3i, Mucosal, Mutation, Receptors, Signal Transducing, Staphylococcal Infections, Staphylococcus, Starvation, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila melanogaster is a useful model to investigate mucosal immunity. The immune response to intestinal infections is mediated partly by the Immune deficiency (IMD) pathway, which only gets activated by a type of peptidoglycan lacking in several medically important Gram-positive bacterial species such as Staphylococcus. Thus, the intestinal host defense against such bacterial strains remains poorly known. Here, we have used Staphylococcus xylosus to develop a model of intestinal infections by Gram-positive bacteria. S. xylosus behaves as an opportunistic pathogen in a septic injury model, being able to kill only flies immunodeficient either for the Toll pathway or the cellular response. When ingested, it is controlled by IMD-independent host intestinal defenses, yet flies eventually die. Having excluded an overreaction of the immune response and the action of toxins, we find that flies actually succumb to starvation, likely as a result of a competition for sucrose between the bacteria and the flies. Fat stores of wild-type flies are severely reduced within a day, a period when sucrose is not yet exhausted in the feeding solution. Interestingly, the Toll pathway mutant MyD88 is more resistant to the ingestion of S. xylosus and to starvation than wild-type flies. MyD88 flies do not rapidly deplete their fat stores when starved, in contrast to wild-type flies. Thus, we have uncovered a novel function of MyD88 in the regulation of metabolism that appears to be independent of its known roles in immunity and development. |
2012 |
Lemaitre, Bruno; Nicolas, Emmanuelle; Michaut, Lydia; Reichhart, Jean-Marc; Hoffmann, Jules A Pillars article: the dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults. Cell. 1996. 86: 973-983 Article de journal J. Immunol., 188 (11), p. 5210–5220, 2012, ISSN: 1550-6606. Résumé | BibTeX | Étiquettes: Animals, Antifungal Agents, Developmental, DNA-Binding Proteins, Gene Expression Regulation, history, hoffmann, M3i, Multigene Family, Mycoses, Phosphoproteins, reichhart, Toll-Like Receptors @article{lemaitre_pillars_2012, title = {Pillars article: the dorsoventral regulatory gene cassette spätzle/Toll/cactus controls the potent antifungal response in Drosophila adults. Cell. 1996. 86: 973-983}, author = {Bruno Lemaitre and Emmanuelle Nicolas and Lydia Michaut and Jean-Marc Reichhart and Jules A Hoffmann}, issn = {1550-6606}, year = {2012}, date = {2012-06-01}, journal = {J. Immunol.}, volume = {188}, number = {11}, pages = {5210--5220}, abstract = {The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle regulatory gene cassette, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways.}, keywords = {Animals, Antifungal Agents, Developmental, DNA-Binding Proteins, Gene Expression Regulation, history, hoffmann, M3i, Multigene Family, Mycoses, Phosphoproteins, reichhart, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The cytokine-induced activation cascade of NF-kappaB in mammals and the activation of the morphogen dorsal in Drosophila embryos show striking structural and functional similarities (Toll/IL-1, Cactus/I-kappaB, and dorsal/NF-kappaB). Here we demonstrate that these parallels extend to the immune response of Drosophila. In particular, the intracellular components of the dorsoventral signaling pathway (except for dorsal) and the extracellular Toll ligand, spätzle regulatory gene cassette, control expression of the antifungal peptide gene drosomycin in adults. We also show that mutations in the Toll signaling pathway dramatically reduce survival after fungal infection. Antibacterial genes are induced either by a distinct pathway involving the immune deficiency gene (imd) or by combined activation of both imd and dorsoventral pathways. |
Coste, Franck; Kemp, Cordula; Bobezeau, Vanessa; Hetru, Charles; Kellenberger, Christine; Imler, Jean-Luc; Roussel, Alain Crystal structure of Diedel, a marker of the immune response of Drosophila melanogaster Article de journal PloS One, 7 (3), p. e33416, 2012, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Animals, Aphids, Crystallography, imler, Janus Kinases, M3i, Protein Folding, Protein Structure, Signal Transduction, STAT Transcription Factors, Tertiary, Transcription Factors, X-Ray @article{coste_crystal_2012, title = {Crystal structure of Diedel, a marker of the immune response of Drosophila melanogaster}, author = {Franck Coste and Cordula Kemp and Vanessa Bobezeau and Charles Hetru and Christine Kellenberger and Jean-Luc Imler and Alain Roussel}, doi = {10.1371/journal.pone.0033416}, issn = {1932-6203}, year = {2012}, date = {2012-01-01}, journal = {PloS One}, volume = {7}, number = {3}, pages = {e33416}, abstract = {BACKGROUND: The Drosophila melanogaster gene CG11501 is up regulated after a septic injury and was proposed to act as a negative regulator of the JAK/STAT signaling pathway. Diedel, the CG11501 gene product, is a small protein of 115 residues with 10 cysteines. METHODOLOGY/PRINCIPAL FINDINGS: We have produced Diedel in Drosophila S2 cells as an extra cellular protein thanks to its own signal peptide and solved its crystal structure at 1.15 Å resolution by SIRAS using an iodo derivative. Diedel is composed of two sub domains SD1 and SD2. SD1 is made of an antiparallel β-sheet covered by an α-helix and displays a ferredoxin-like fold. SD2 reveals a new protein fold made of loops connected by four disulfide bridges. Further structural analysis identified conserved hydrophobic residues on the surface of Diedel that may constitute a potential binding site. The existence of two conformations, cis and trans, for the proline 52 may be of interest as prolyl peptidyl isomerisation has been shown to play a role in several physiological mechanisms. The genome of D. melanogaster contains two other genes coding for proteins homologous to Diedel, namely CG43228 and CG34329. Strikingly, apart from Drosophila and the pea aphid Acyrthosiphon pisum, Diedel-related sequences were exclusively identified in a few insect DNA viruses of the Baculoviridae and Ascoviridae families. CONCLUSION/SIGNIFICANCE: Diedel, a marker of the Drosophila antimicrobial/antiviral response, is a member of a small family of proteins present in drosophilids, aphids and DNA viruses infecting lepidopterans. Diedel is an extracellular protein composed of two sub-domains. Two special structural features (hydrophobic surface patch and cis/trans conformation for proline 52) may indicate a putative interaction site, and support an extra cellular signaling function for Diedel, which is in accordance with its proposed role as negative regulator of the JAK/STAT signaling pathway.}, keywords = {Animals, Aphids, Crystallography, imler, Janus Kinases, M3i, Protein Folding, Protein Structure, Signal Transduction, STAT Transcription Factors, Tertiary, Transcription Factors, X-Ray}, pubstate = {published}, tppubtype = {article} } BACKGROUND: The Drosophila melanogaster gene CG11501 is up regulated after a septic injury and was proposed to act as a negative regulator of the JAK/STAT signaling pathway. Diedel, the CG11501 gene product, is a small protein of 115 residues with 10 cysteines. METHODOLOGY/PRINCIPAL FINDINGS: We have produced Diedel in Drosophila S2 cells as an extra cellular protein thanks to its own signal peptide and solved its crystal structure at 1.15 Å resolution by SIRAS using an iodo derivative. Diedel is composed of two sub domains SD1 and SD2. SD1 is made of an antiparallel β-sheet covered by an α-helix and displays a ferredoxin-like fold. SD2 reveals a new protein fold made of loops connected by four disulfide bridges. Further structural analysis identified conserved hydrophobic residues on the surface of Diedel that may constitute a potential binding site. The existence of two conformations, cis and trans, for the proline 52 may be of interest as prolyl peptidyl isomerisation has been shown to play a role in several physiological mechanisms. The genome of D. melanogaster contains two other genes coding for proteins homologous to Diedel, namely CG43228 and CG34329. Strikingly, apart from Drosophila and the pea aphid Acyrthosiphon pisum, Diedel-related sequences were exclusively identified in a few insect DNA viruses of the Baculoviridae and Ascoviridae families. CONCLUSION/SIGNIFICANCE: Diedel, a marker of the Drosophila antimicrobial/antiviral response, is a member of a small family of proteins present in drosophilids, aphids and DNA viruses infecting lepidopterans. Diedel is an extracellular protein composed of two sub-domains. Two special structural features (hydrophobic surface patch and cis/trans conformation for proline 52) may indicate a putative interaction site, and support an extra cellular signaling function for Diedel, which is in accordance with its proposed role as negative regulator of the JAK/STAT signaling pathway. |
Deleury, Emeline; Dubreuil, Géraldine; Elangovan, Namasivayam; Wajnberg, Eric; Reichhart, Jean-Marc; Gourbal, Benjamin; Duval, David; Baron, Olga Lucia; Gouzy, Jérôme; Coustau, Christine Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study Article de journal PLoS ONE, 7 (3), p. e32512, 2012, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers @article{deleury_specific_2012, title = {Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study}, author = {Emeline Deleury and Géraldine Dubreuil and Namasivayam Elangovan and Eric Wajnberg and Jean-Marc Reichhart and Benjamin Gourbal and David Duval and Olga Lucia Baron and Jérôme Gouzy and Christine Coustau}, doi = {10.1371/journal.pone.0032512}, issn = {1932-6203}, year = {2012}, date = {2012-01-01}, journal = {PLoS ONE}, volume = {7}, number = {3}, pages = {e32512}, abstract = {Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.}, keywords = {Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers}, pubstate = {published}, tppubtype = {article} } Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses. |
Liu, Xi; Sano, Teruyuki; Guan, Yongsheng; Nagata, Shigekazu; Hoffmann, Jules A; Fukuyama, Hidehiro Drosophila EYA regulates the immune response against DNA through an evolutionarily conserved threonine phosphatase motif Article de journal PLoS ONE, 7 (8), p. e42725, 2012, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Blotting, Conserved Sequence, Endodeoxyribonucleases, Eye Proteins, hoffmann, Immunoprecipitation, M3i, Phosphoprotein Phosphatases, Sequence Homology, Transcription Factors, Western @article{liu_drosophila_2012, title = {Drosophila EYA regulates the immune response against DNA through an evolutionarily conserved threonine phosphatase motif}, author = {Xi Liu and Teruyuki Sano and Yongsheng Guan and Shigekazu Nagata and Jules A Hoffmann and Hidehiro Fukuyama}, doi = {10.1371/journal.pone.0042725}, issn = {1932-6203}, year = {2012}, date = {2012-01-01}, journal = {PLoS ONE}, volume = {7}, number = {8}, pages = {e42725}, abstract = {Innate immune responses against DNA are essential to counter both pathogen infections and tissue damages. Mammalian EYAs were recently shown to play a role in regulating the innate immune responses against DNA. Here, we demonstrate that the unique Drosophila eya gene is also involved in the response specific to DNA. Haploinsufficiency of eya in mutants deficient for lysosomal DNase activity (DNaseII) reduces antimicrobial peptide gene expression, a hallmark for immune responses in flies. Like the mammalian orthologues, Drosophila EYA features a N-terminal threonine and C-terminal tyrosine phosphatase domain. Through the generation of a series of mutant EYA fly strains, we show that the threonine phosphatase domain, but not the tyrosine phosphatase domain, is responsible for the innate immune response against DNA. A similar role for the threonine phosphatase domain in mammalian EYA4 had been surmised on the basis of in vitro studies. Furthermore EYA associates with IKKβ and full-length RELISH, and the induction of the IMD pathway-dependent antimicrobial peptide gene is independent of SO. Our data provide the first in vivo demonstration for the immune function of EYA and point to their conserved immune function in response to endogenous DNA, throughout evolution.}, keywords = {Amino Acid, Animals, Blotting, Conserved Sequence, Endodeoxyribonucleases, Eye Proteins, hoffmann, Immunoprecipitation, M3i, Phosphoprotein Phosphatases, Sequence Homology, Transcription Factors, Western}, pubstate = {published}, tppubtype = {article} } Innate immune responses against DNA are essential to counter both pathogen infections and tissue damages. Mammalian EYAs were recently shown to play a role in regulating the innate immune responses against DNA. Here, we demonstrate that the unique Drosophila eya gene is also involved in the response specific to DNA. Haploinsufficiency of eya in mutants deficient for lysosomal DNase activity (DNaseII) reduces antimicrobial peptide gene expression, a hallmark for immune responses in flies. Like the mammalian orthologues, Drosophila EYA features a N-terminal threonine and C-terminal tyrosine phosphatase domain. Through the generation of a series of mutant EYA fly strains, we show that the threonine phosphatase domain, but not the tyrosine phosphatase domain, is responsible for the innate immune response against DNA. A similar role for the threonine phosphatase domain in mammalian EYA4 had been surmised on the basis of in vitro studies. Furthermore EYA associates with IKKβ and full-length RELISH, and the induction of the IMD pathway-dependent antimicrobial peptide gene is independent of SO. Our data provide the first in vivo demonstration for the immune function of EYA and point to their conserved immune function in response to endogenous DNA, throughout evolution. |
Niehus, Sebastian; Giammarinaro, Philippe; Liégeois, Samuel; Quintin, Jessica; Ferrandon, Dominique Fly culture collapse disorder: detection, prophylaxis and eradication of the microsporidian parasite Tubulinosema ratisbonensis infecting Drosophila melanogaster Article de journal Fly (Austin), 6 (3), p. 193–204, 2012, ISSN: 1933-6942. Résumé | Liens | BibTeX | Étiquettes: Animals, Apansporoblastina, Apansporoblastina/*genetics/physiology, Base Sequence, cure, Disinfection, Disinfection/methods, DNA, DNA Primers, Drosophila melanogaster/*microbiology, ferrandon, fumagillin, Fungal, Fungal/chemistry, M3i, microsporidia, obligate intracellular parasitism, PCR detection, Phylogeny, Polymerase Chain Reaction, Polymerase Chain Reaction/methods, prophylaxis, Ribosomal, Ribosomal/chemistry, Sequence Alignment, Tubulinosema ratisbonensis @article{niehus_fly_2012b, title = {Fly culture collapse disorder: detection, prophylaxis and eradication of the microsporidian parasite Tubulinosema ratisbonensis infecting Drosophila melanogaster}, author = {Sebastian Niehus and Philippe Giammarinaro and Samuel Liégeois and Jessica Quintin and Dominique Ferrandon}, doi = {10.4161/fly.20896}, issn = {1933-6942}, year = {2012}, date = {2012-01-01}, journal = {Fly (Austin)}, volume = {6}, number = {3}, pages = {193--204}, abstract = {Drosophila melanogaster is a robust model to investigate many biological problems. It is however prone to some infections, which may endanger fly stocks if left unchecked for. One such infection is caused by an obligate fungal intracellular parasite, Tubulinosema ratisbonensis, which can be found in laboratory stocks. Here, we identify and briefly characterize a T. ratisbonensis strain that was infesting our Drosophila cultures and that required intensive measures to contain and eradicate the infection. We describe the phenotypes of infested stocks. We also report PCR-based techniques that allow the detection of infested stocks with a high sensitivity. We have developed a high-throughput qPCR assay that allows the efficient parallel screening of a large number of potentially-infested stocks. We also have investigated several prophylactic measures to prevent the further contamination of stocks, namely UV-exposure, ethanol treatment, bleaching, and desiccation. Bleaching was found to kill all spores. Other treatments were less effective but were found to be sufficient to prevent further contamination of noninfested stocks. Two treatments were efficacious in curing infested stocks (1) bleaching of eggs and subsequent raising of the larvae in clean vials; (2) fumagillin treatment. These cures only work on stocks that have not become too weak to withstand the procedures.}, keywords = {Animals, Apansporoblastina, Apansporoblastina/*genetics/physiology, Base Sequence, cure, Disinfection, Disinfection/methods, DNA, DNA Primers, Drosophila melanogaster/*microbiology, ferrandon, fumagillin, Fungal, Fungal/chemistry, M3i, microsporidia, obligate intracellular parasitism, PCR detection, Phylogeny, Polymerase Chain Reaction, Polymerase Chain Reaction/methods, prophylaxis, Ribosomal, Ribosomal/chemistry, Sequence Alignment, Tubulinosema ratisbonensis}, pubstate = {published}, tppubtype = {article} } Drosophila melanogaster is a robust model to investigate many biological problems. It is however prone to some infections, which may endanger fly stocks if left unchecked for. One such infection is caused by an obligate fungal intracellular parasite, Tubulinosema ratisbonensis, which can be found in laboratory stocks. Here, we identify and briefly characterize a T. ratisbonensis strain that was infesting our Drosophila cultures and that required intensive measures to contain and eradicate the infection. We describe the phenotypes of infested stocks. We also report PCR-based techniques that allow the detection of infested stocks with a high sensitivity. We have developed a high-throughput qPCR assay that allows the efficient parallel screening of a large number of potentially-infested stocks. We also have investigated several prophylactic measures to prevent the further contamination of stocks, namely UV-exposure, ethanol treatment, bleaching, and desiccation. Bleaching was found to kill all spores. Other treatments were less effective but were found to be sufficient to prevent further contamination of noninfested stocks. Two treatments were efficacious in curing infested stocks (1) bleaching of eggs and subsequent raising of the larvae in clean vials; (2) fumagillin treatment. These cures only work on stocks that have not become too weak to withstand the procedures. |
Meister, Marie; Ferrandon, Dominique Immune cell transdifferentiation: a complex crosstalk between circulating immune cells and the haematopoietic niche Article de journal EMBO Rep., 13 (1), p. 3–4, 2012, ISSN: 1469-3178. Liens | BibTeX | Étiquettes: Animals, Cell Communication, Cell Transdifferentiation, ferrandon, Hematopoietic Stem Cells, Humans, Immune System, M3i, Signal Transduction, Stem Cell Niche @article{meister_immune_2012, title = {Immune cell transdifferentiation: a complex crosstalk between circulating immune cells and the haematopoietic niche}, author = {Marie Meister and Dominique Ferrandon}, doi = {10.1038/embor.2011.238}, issn = {1469-3178}, year = {2012}, date = {2012-01-01}, journal = {EMBO Rep.}, volume = {13}, number = {1}, pages = {3--4}, keywords = {Animals, Cell Communication, Cell Transdifferentiation, ferrandon, Hematopoietic Stem Cells, Humans, Immune System, M3i, Signal Transduction, Stem Cell Niche}, pubstate = {published}, tppubtype = {article} } |
2011 |
Limmer, Stefanie; Haller, Samantha; Drenkard, Eliana; Lee, Janice; Yu, Shen; Kocks, Christine; Ausubel, Frederick M; Ferrandon, Dominique Pseudomonas aeruginosa RhlR is required to neutralize the cellular immune response in a Drosophila melanogaster oral infection model Article de journal Proc. Natl. Acad. Sci. U.S.A., 108 (42), p. 17378–17383, 2011, ISSN: 1091-6490. Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Bacteremia, Bacterial Proteins, Cellular, Disease Models, ferrandon, Genes, Genetically Modified, Hemolymph, Host-Pathogen Interactions, Immunity, Insect, M3i, Mutation, Oral, Pseudomonas aeruginosa, Pseudomonas Infections, Quorum Sensing, Trans-Activators, Viral, Virulence @article{limmer_pseudomonas_2011b, title = {Pseudomonas aeruginosa RhlR is required to neutralize the cellular immune response in a Drosophila melanogaster oral infection model}, author = {Stefanie Limmer and Samantha Haller and Eliana Drenkard and Janice Lee and Shen Yu and Christine Kocks and Frederick M Ausubel and Dominique Ferrandon}, doi = {10.1073/pnas.1114907108}, issn = {1091-6490}, year = {2011}, date = {2011-10-01}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, volume = {108}, number = {42}, pages = {17378--17383}, abstract = {An in-depth mechanistic understanding of microbial infection necessitates a molecular dissection of host-pathogen relationships. Both Drosophila melanogaster and Pseudomonas aeruginosa have been intensively studied. Here, we analyze the infection of D. melanogaster by P. aeruginosa by using mutants in both host and pathogen. We show that orally ingested P. aeruginosa crosses the intestinal barrier and then proliferates in the hemolymph, thereby causing the infected flies to die of bacteremia. Host defenses against ingested P. aeruginosa included an immune deficiency (IMD) response in the intestinal epithelium, systemic Toll and IMD pathway responses, and a cellular immune response controlling bacteria in the hemocoel. Although the observed cellular and intestinal immune responses appeared to act throughout the course of the infection, there was a late onset of the systemic IMD and Toll responses. In this oral infection model, P. aeruginosa PA14 did not require its type III secretion system or other well-studied virulence factors such as the two-component response regulator GacA or the protease AprA for virulence. In contrast, the quorum-sensing transcription factor RhlR, but surprisingly not LasR, played a key role in counteracting the cellular immune response against PA14, possibly at an early stage when only a few bacteria are present in the hemocoel. These results illustrate the power of studying infection from the dual perspective of host and pathogen by revealing that RhlR plays a more complex role during pathogenesis than previously appreciated.}, keywords = {Animal, Animals, Bacteremia, Bacterial Proteins, Cellular, Disease Models, ferrandon, Genes, Genetically Modified, Hemolymph, Host-Pathogen Interactions, Immunity, Insect, M3i, Mutation, Oral, Pseudomonas aeruginosa, Pseudomonas Infections, Quorum Sensing, Trans-Activators, Viral, Virulence}, pubstate = {published}, tppubtype = {article} } An in-depth mechanistic understanding of microbial infection necessitates a molecular dissection of host-pathogen relationships. Both Drosophila melanogaster and Pseudomonas aeruginosa have been intensively studied. Here, we analyze the infection of D. melanogaster by P. aeruginosa by using mutants in both host and pathogen. We show that orally ingested P. aeruginosa crosses the intestinal barrier and then proliferates in the hemolymph, thereby causing the infected flies to die of bacteremia. Host defenses against ingested P. aeruginosa included an immune deficiency (IMD) response in the intestinal epithelium, systemic Toll and IMD pathway responses, and a cellular immune response controlling bacteria in the hemocoel. Although the observed cellular and intestinal immune responses appeared to act throughout the course of the infection, there was a late onset of the systemic IMD and Toll responses. In this oral infection model, P. aeruginosa PA14 did not require its type III secretion system or other well-studied virulence factors such as the two-component response regulator GacA or the protease AprA for virulence. In contrast, the quorum-sensing transcription factor RhlR, but surprisingly not LasR, played a key role in counteracting the cellular immune response against PA14, possibly at an early stage when only a few bacteria are present in the hemocoel. These results illustrate the power of studying infection from the dual perspective of host and pathogen by revealing that RhlR plays a more complex role during pathogenesis than previously appreciated. |
Chtarbanova, Stanislava; Imler, Jean-Luc Microbial sensing by Toll receptors: a historical perspective Article de journal Arteriosclerosis, Thrombosis, and Vascular Biology, 31 (8), p. 1734–1738, 2011, ISSN: 1524-4636. Résumé | Liens | BibTeX | Étiquettes: Animals, Cardiovascular Diseases, history, Host-Pathogen Interactions, Humans, imler, Immunity, Innate, M3i, Macrophages, Toll-Like Receptors @article{chtarbanova_microbial_2011, title = {Microbial sensing by Toll receptors: a historical perspective}, author = {Stanislava Chtarbanova and Jean-Luc Imler}, doi = {10.1161/ATVBAHA.108.179523}, issn = {1524-4636}, year = {2011}, date = {2011-08-01}, journal = {Arteriosclerosis, Thrombosis, and Vascular Biology}, volume = {31}, number = {8}, pages = {1734--1738}, abstract = {The family of Toll-like receptors plays an essential role in the induction of the immune response. These receptors sense the presence of microbial ligands and activate the nuclear factor-κB transcription factor. We review the key studies that led from the formulation of the concept of pattern recognition receptors to the characterization of Toll-like receptors, insisting on the important role played by the model organism Drosophila melanogaster and on the increasing evidence connecting these receptors to cardiovascular disease.}, keywords = {Animals, Cardiovascular Diseases, history, Host-Pathogen Interactions, Humans, imler, Immunity, Innate, M3i, Macrophages, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The family of Toll-like receptors plays an essential role in the induction of the immune response. These receptors sense the presence of microbial ligands and activate the nuclear factor-κB transcription factor. We review the key studies that led from the formulation of the concept of pattern recognition receptors to the characterization of Toll-like receptors, insisting on the important role played by the model organism Drosophila melanogaster and on the increasing evidence connecting these receptors to cardiovascular disease. |
Eleftherianos, Ioannis; Won, Sungyong; Chtarbanova, Stanislava; Squiban, Barbara; Ocorr, Karen; Bodmer, Rolf; Beutler, Bruce; Hoffmann, Jules A; Imler, Jean-Luc ATP-sensitive potassium channel (K(ATP))-dependent regulation of cardiotropic viral infections Article de journal Proceedings of the National Academy of Sciences of the United States of America, 108 (29), p. 12024–12029, 2011, ISSN: 1091-6490. Résumé | Liens | BibTeX | Étiquettes: Animals, Heart, HeLa Cells, hoffmann, Humans, imler, Immunity, Immunoblotting, Inbred C57BL, Innate, KATP Channels, M3i, Mice, Nodaviridae, Pinacidil, Reverse Transcriptase Polymerase Chain Reaction, RNA Interference, Tolbutamide, Viral Load, Viremia @article{eleftherianos_atp-sensitive_2011, title = {ATP-sensitive potassium channel (K(ATP))-dependent regulation of cardiotropic viral infections}, author = {Ioannis Eleftherianos and Sungyong Won and Stanislava Chtarbanova and Barbara Squiban and Karen Ocorr and Rolf Bodmer and Bruce Beutler and Jules A Hoffmann and Jean-Luc Imler}, doi = {10.1073/pnas.1108926108}, issn = {1091-6490}, year = {2011}, date = {2011-07-01}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, number = {29}, pages = {12024--12029}, abstract = {The effects of the cellular environment on innate immunity remain poorly characterized. Here, we show that in Drosophila ATP-sensitive potassium channels (K(ATP)) mediate resistance to a cardiotropic RNA virus, Flock House virus (FHV). FHV viral load in the heart rapidly increases in K(ATP) mutant flies, leading to increased viremia and accelerated death. The effect of K(ATP) channels is dependent on the RNA interference genes Dcr-2, AGO2, and r2d2, indicating that an activity associated with this potassium channel participates in this antiviral pathway in Drosophila. Flies treated with the K(ATP) agonist drug pinacidil are protected against FHV infection, thus demonstrating the importance of this regulation of innate immunity by the cellular environment in the heart. In mice, the Coxsackievirus B3 replicates to higher titers in the hearts of mayday mutant animals, which are deficient in the Kir6.1 subunit of K(ATP) channels, than in controls. Together, our data suggest that K(ATP) channel deregulation can have a critical impact on innate antiviral immunity in the heart.}, keywords = {Animals, Heart, HeLa Cells, hoffmann, Humans, imler, Immunity, Immunoblotting, Inbred C57BL, Innate, KATP Channels, M3i, Mice, Nodaviridae, Pinacidil, Reverse Transcriptase Polymerase Chain Reaction, RNA Interference, Tolbutamide, Viral Load, Viremia}, pubstate = {published}, tppubtype = {article} } The effects of the cellular environment on innate immunity remain poorly characterized. Here, we show that in Drosophila ATP-sensitive potassium channels (K(ATP)) mediate resistance to a cardiotropic RNA virus, Flock House virus (FHV). FHV viral load in the heart rapidly increases in K(ATP) mutant flies, leading to increased viremia and accelerated death. The effect of K(ATP) channels is dependent on the RNA interference genes Dcr-2, AGO2, and r2d2, indicating that an activity associated with this potassium channel participates in this antiviral pathway in Drosophila. Flies treated with the K(ATP) agonist drug pinacidil are protected against FHV infection, thus demonstrating the importance of this regulation of innate immunity by the cellular environment in the heart. In mice, the Coxsackievirus B3 replicates to higher titers in the hearts of mayday mutant animals, which are deficient in the Kir6.1 subunit of K(ATP) channels, than in controls. Together, our data suggest that K(ATP) channel deregulation can have a critical impact on innate antiviral immunity in the heart. |
Limmer, Stefanie; Quintin, Jessica; Hetru, Charles; Ferrandon, Dominique Virulence on the fly: Drosophila melanogaster as a model genetic organism to decipher host-pathogen interactions Article de journal Curr Drug Targets, 12 (7), p. 978–999, 2011, ISSN: 1873-5592. Résumé | BibTeX | Étiquettes: Animal, Animals, Anti-Infective Agents, Disease Models, Drug Delivery Systems, Drug Design, Drug Resistance, ferrandon, Fungi, High-Throughput Screening Assays, Host-Pathogen Interactions, Humans, M3i, Microbial, Pseudomonas aeruginosa @article{limmer_virulence_2011b, title = {Virulence on the fly: Drosophila melanogaster as a model genetic organism to decipher host-pathogen interactions}, author = {Stefanie Limmer and Jessica Quintin and Charles Hetru and Dominique Ferrandon}, issn = {1873-5592}, year = {2011}, date = {2011-06-01}, journal = {Curr Drug Targets}, volume = {12}, number = {7}, pages = {978--999}, abstract = {To gain an in-depth grasp of infectious processes one has to know the specific interactions between the virulence factors of the pathogen and the host defense mechanisms. A thorough understanding is crucial for identifying potential new drug targets and designing drugs against which the pathogens might not develop resistance easily. Model organisms are a useful tool for this endeavor, thanks to the power of their genetics. Drosophila melanogaster is widely used to study host-pathogen interactions. Its basal immune response is well understood and is briefly reviewed here. Considerations relevant to choosing an adequate infection model are discussed. This review then focuses mainly on infections with two categories of pathogens, the well-studied Gram-negative bacterium Pseudomonas aeruginosa and infections by fungi of medical interest. These examples provide an overview over the current knowledge on Drosophila-pathogen interactions and illustrate the approaches that can be used to study those interactions. We also discuss the usefulness and limits of Drosophila infection models for studying specific host-pathogen interactions and high-throughput drug screening.}, keywords = {Animal, Animals, Anti-Infective Agents, Disease Models, Drug Delivery Systems, Drug Design, Drug Resistance, ferrandon, Fungi, High-Throughput Screening Assays, Host-Pathogen Interactions, Humans, M3i, Microbial, Pseudomonas aeruginosa}, pubstate = {published}, tppubtype = {article} } To gain an in-depth grasp of infectious processes one has to know the specific interactions between the virulence factors of the pathogen and the host defense mechanisms. A thorough understanding is crucial for identifying potential new drug targets and designing drugs against which the pathogens might not develop resistance easily. Model organisms are a useful tool for this endeavor, thanks to the power of their genetics. Drosophila melanogaster is widely used to study host-pathogen interactions. Its basal immune response is well understood and is briefly reviewed here. Considerations relevant to choosing an adequate infection model are discussed. This review then focuses mainly on infections with two categories of pathogens, the well-studied Gram-negative bacterium Pseudomonas aeruginosa and infections by fungi of medical interest. These examples provide an overview over the current knowledge on Drosophila-pathogen interactions and illustrate the approaches that can be used to study those interactions. We also discuss the usefulness and limits of Drosophila infection models for studying specific host-pathogen interactions and high-throughput drug screening. |
Ogawa, Michinaga; Yoshikawa, Yuko; Kobayashi, Taira; Mimuro, Hitomi; Fukumatsu, Makoto; Kiga, Kotaro; Piao, Zhenzi; Ashida, Hiroshi; Yoshida, Mitsutaka; Kakuta, Shigeru; Koyama, Tomohiro; Goto, Yoshiyuki; Nagatake, Takahiro; Nagai, Shinya; Kiyono, Hiroshi; Kawalec, Magdalena; Reichhart, Jean-Marc; Sasakawa, Chihiro A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens Article de journal Cell Host Microbe, 9 (5), p. 376–389, 2011, ISSN: 1934-6069. Résumé | Liens | BibTeX | Étiquettes: Animals, Autophagy, Biological, Cells, Cultured, M3i, Membrane Proteins, Mice, Microtubule-Associated Proteins, Models, Phagosomes, Protein Interaction Mapping, reichhart, Shigella, Two-Hybrid System Techniques @article{ogawa_tecpr1-dependent_2011, title = {A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens}, author = {Michinaga Ogawa and Yuko Yoshikawa and Taira Kobayashi and Hitomi Mimuro and Makoto Fukumatsu and Kotaro Kiga and Zhenzi Piao and Hiroshi Ashida and Mitsutaka Yoshida and Shigeru Kakuta and Tomohiro Koyama and Yoshiyuki Goto and Takahiro Nagatake and Shinya Nagai and Hiroshi Kiyono and Magdalena Kawalec and Jean-Marc Reichhart and Chihiro Sasakawa}, doi = {10.1016/j.chom.2011.04.010}, issn = {1934-6069}, year = {2011}, date = {2011-05-01}, journal = {Cell Host Microbe}, volume = {9}, number = {5}, pages = {376--389}, abstract = {Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy.}, keywords = {Animals, Autophagy, Biological, Cells, Cultured, M3i, Membrane Proteins, Mice, Microtubule-Associated Proteins, Models, Phagosomes, Protein Interaction Mapping, reichhart, Shigella, Two-Hybrid System Techniques}, pubstate = {published}, tppubtype = {article} } Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy. |
Kellenberger, Christine; Leone, Philippe; Coquet, Laurent; Jouenne, Thierry; Reichhart, Jean-Marc; Roussel, Alain Structure-function analysis of grass clip serine protease involved in Drosophila Toll pathway activation Article de journal J. Biol. Chem., 286 (14), p. 12300–12307, 2011, ISSN: 1083-351X. Résumé | Liens | BibTeX | Étiquettes: Animals, Catalytic Domain, Cell Line, M3i, reichhart, Serine Proteases, Signal Transduction, Structure-Activity Relationship, Toll-Like Receptors @article{kellenberger_structure-function_2011, title = {Structure-function analysis of grass clip serine protease involved in Drosophila Toll pathway activation}, author = {Christine Kellenberger and Philippe Leone and Laurent Coquet and Thierry Jouenne and Jean-Marc Reichhart and Alain Roussel}, doi = {10.1074/jbc.M110.182741}, issn = {1083-351X}, year = {2011}, date = {2011-04-01}, journal = {J. Biol. Chem.}, volume = {286}, number = {14}, pages = {12300--12307}, abstract = {Grass is a clip domain serine protease (SP) involved in a proteolytic cascade triggering the Toll pathway activation of Drosophila during an immune response. Epistasic studies position it downstream of the apical protease ModSP and upstream of the terminal protease Spaetzle-processing enzyme. Here, we report the crystal structure of Grass zymogen. We found that Grass displays a rather deep active site cleft comparable with that of proteases of coagulation and complement cascades. A key distinctive feature is the presence of an additional loop (75-loop) in the proximity of the activation site localized on a protruding loop. All biochemical attempts to hydrolyze the activation site of Grass failed, strongly suggesting restricted access to this region. The 75-loop is thus proposed to constitute an original mechanism to prevent spontaneous activation. A comparison of Grass with clip serine proteases of known function involved in analogous proteolytic cascades allowed us to define two groups, according to the presence of the 75-loop and the conformation of the clip domain. One group (devoid of the 75-loop) contains penultimate proteases whereas the other contains terminal proteases. Using this classification, Grass appears to be a terminal protease. This result is evaluated according to the genetic data documenting Grass function.}, keywords = {Animals, Catalytic Domain, Cell Line, M3i, reichhart, Serine Proteases, Signal Transduction, Structure-Activity Relationship, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Grass is a clip domain serine protease (SP) involved in a proteolytic cascade triggering the Toll pathway activation of Drosophila during an immune response. Epistasic studies position it downstream of the apical protease ModSP and upstream of the terminal protease Spaetzle-processing enzyme. Here, we report the crystal structure of Grass zymogen. We found that Grass displays a rather deep active site cleft comparable with that of proteases of coagulation and complement cascades. A key distinctive feature is the presence of an additional loop (75-loop) in the proximity of the activation site localized on a protruding loop. All biochemical attempts to hydrolyze the activation site of Grass failed, strongly suggesting restricted access to this region. The 75-loop is thus proposed to constitute an original mechanism to prevent spontaneous activation. A comparison of Grass with clip serine proteases of known function involved in analogous proteolytic cascades allowed us to define two groups, according to the presence of the 75-loop and the conformation of the clip domain. One group (devoid of the 75-loop) contains penultimate proteases whereas the other contains terminal proteases. Using this classification, Grass appears to be a terminal protease. This result is evaluated according to the genetic data documenting Grass function. |
Aoun, Richard Bou; Hetru, Charles; Troxler, Laurent; Doucet, Daniel; Ferrandon, Dominique; Matt, Nicolas Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster Article de journal J Innate Immun, 3 (1), p. 52–64, 2011, ISSN: 1662-8128. Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis @article{bou_aoun_analysis_2011, title = {Analysis of thioester-containing proteins during the innate immune response of Drosophila melanogaster}, author = {Richard Bou Aoun and Charles Hetru and Laurent Troxler and Daniel Doucet and Dominique Ferrandon and Nicolas Matt}, doi = {10.1159/000321554}, issn = {1662-8128}, year = {2011}, date = {2011-01-01}, journal = {J Innate Immun}, volume = {3}, number = {1}, pages = {52--64}, abstract = {Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila.}, keywords = {Animals, bioinformatic, DNA, Evolution, ferrandon, Gene Expression Regulation, Hemocytes, Immunity, In Situ Hybridization, Innate, M3i, matt, Molecular, Mutation, Phylogeny, Sequence Analysis}, pubstate = {published}, tppubtype = {article} } Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1-Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila. |
Reichhart, Jean-Marc; Gubb, David; Leclerc, Vincent The Drosophila serpins: multiple functions in immunity and morphogenesis Article de journal Meth. Enzymol., 499 , p. 205–225, 2011, ISSN: 1557-7988. Résumé | Liens | BibTeX | Étiquettes: Animals, Immunity, Innate, M3i, Morphogenesis, reichhart, Serpins, Signal Transduction @article{reichhart_drosophila_2011, title = {The Drosophila serpins: multiple functions in immunity and morphogenesis}, author = {Jean-Marc Reichhart and David Gubb and Vincent Leclerc}, doi = {10.1016/B978-0-12-386471-0.00011-0}, issn = {1557-7988}, year = {2011}, date = {2011-01-01}, journal = {Meth. Enzymol.}, volume = {499}, pages = {205--225}, abstract = {Members of the serpin superfamily of proteins have been found in all living organisms, although rarely in bacteria or fungi. They have been extensively studied in mammals, where many rapid physiological responses are regulated by inhibitory serpins. In addition to the inhibitory serpins, a large group of noninhibitory proteins with a conserved serpin fold have also been identified in mammals. These noninhibitory proteins have a wide range of functions, from storage proteins to molecular chaperones, hormone transporters, and tumor suppressors. In contrast, until recently, very little was known about insect serpins in general, or Drosophila serpins in particular. In the last decade, however, there has been an increasing interest in the serpin biology of insects. It is becoming clear that, like in mammals, a similar wide range of physiological responses are regulated in insects and that noninhibitory serpin-fold proteins also play key roles in insect biology. Drosophila is also an important model organism that can be used to study human pathologies (among which serpinopathies or other protein conformational diseases) and mechanisms of regulation of proteolytic cascades in health or to develop strategies for control of insect pests and disease vectors. As most of our knowledge on insect serpins comes from studies on the Drosophila immune response, we survey here the Drosophila serpin literature and describe the laboratory techniques that have been developed to study serpin-regulated responses in this model genetic organism.}, keywords = {Animals, Immunity, Innate, M3i, Morphogenesis, reichhart, Serpins, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Members of the serpin superfamily of proteins have been found in all living organisms, although rarely in bacteria or fungi. They have been extensively studied in mammals, where many rapid physiological responses are regulated by inhibitory serpins. In addition to the inhibitory serpins, a large group of noninhibitory proteins with a conserved serpin fold have also been identified in mammals. These noninhibitory proteins have a wide range of functions, from storage proteins to molecular chaperones, hormone transporters, and tumor suppressors. In contrast, until recently, very little was known about insect serpins in general, or Drosophila serpins in particular. In the last decade, however, there has been an increasing interest in the serpin biology of insects. It is becoming clear that, like in mammals, a similar wide range of physiological responses are regulated in insects and that noninhibitory serpin-fold proteins also play key roles in insect biology. Drosophila is also an important model organism that can be used to study human pathologies (among which serpinopathies or other protein conformational diseases) and mechanisms of regulation of proteolytic cascades in health or to develop strategies for control of insect pests and disease vectors. As most of our knowledge on insect serpins comes from studies on the Drosophila immune response, we survey here the Drosophila serpin literature and describe the laboratory techniques that have been developed to study serpin-regulated responses in this model genetic organism. |
Lee, Kwang-Zin; Ferrandon, Dominique Negative regulation of immune responses on the fly Article de journal EMBO J., 30 (6), p. 988–990, 2011, ISSN: 1460-2075. Liens | BibTeX | Étiquettes: *Gene Expression Regulation, *Homeostasis, Animals, bacteria, Bacteria/*immunology, Biological, Drosophila melanogaster/*immunology, Drosophila Proteins/biosynthesis/metabolism, ferrandon, Gene Expression Regulation, Homeostasis, M3i, Mitogen-Activated Protein Kinases, Mitogen-Activated Protein Kinases/metabolism, Models, NF-kappa B, NF-kappa B/metabolism, ras Proteins, ras Proteins/metabolism, Receptor Protein-Tyrosine Kinases, Receptor Protein-Tyrosine Kinases/metabolism @article{lee_negative_2011b, title = {Negative regulation of immune responses on the fly}, author = {Kwang-Zin Lee and Dominique Ferrandon}, doi = {10.1038/emboj.2011.47}, issn = {1460-2075}, year = {2011}, date = {2011-01-01}, journal = {EMBO J.}, volume = {30}, number = {6}, pages = {988--990}, keywords = {*Gene Expression Regulation, *Homeostasis, Animals, bacteria, Bacteria/*immunology, Biological, Drosophila melanogaster/*immunology, Drosophila Proteins/biosynthesis/metabolism, ferrandon, Gene Expression Regulation, Homeostasis, M3i, Mitogen-Activated Protein Kinases, Mitogen-Activated Protein Kinases/metabolism, Models, NF-kappa B, NF-kappa B/metabolism, ras Proteins, ras Proteins/metabolism, Receptor Protein-Tyrosine Kinases, Receptor Protein-Tyrosine Kinases/metabolism}, pubstate = {published}, tppubtype = {article} } |
Nehme, Nadine T; Quintin, Jessica; Cho, Ju Hyun; Lee, Janice; Lafarge, Marie-Céline; Kocks, Christine; Ferrandon, Dominique Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections Article de journal PLoS ONE, 6 (3), p. e14743, 2011, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, Carrier Proteins, Cell Surface, Cellular, Enterococcus faecalis, ferrandon, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, Host-Pathogen Interactions, Humoral, Immunity, Innate, M3i, Micrococcus luteus, Opsonin Proteins, Phagocytosis, Receptors, Signal Transduction, Solubility, Staphylococcus aureus @article{nehme_relative_2011b, title = {Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections}, author = {Nadine T Nehme and Jessica Quintin and Ju Hyun Cho and Janice Lee and Marie-Céline Lafarge and Christine Kocks and Dominique Ferrandon}, doi = {10.1371/journal.pone.0014743}, issn = {1932-6203}, year = {2011}, date = {2011-01-01}, journal = {PLoS ONE}, volume = {6}, number = {3}, pages = {e14743}, abstract = {BACKGROUND: Two NF-kappaB signaling pathways, Toll and immune deficiency (imd), are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense. METHODOLOGY/PRINCIPAL FINDINGS: In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus), we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response. CONCLUSIONS/SIGNIFICANCE: Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen.}, keywords = {Animals, Antimicrobial Cationic Peptides, Carrier Proteins, Cell Surface, Cellular, Enterococcus faecalis, ferrandon, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, Host-Pathogen Interactions, Humoral, Immunity, Innate, M3i, Micrococcus luteus, Opsonin Proteins, Phagocytosis, Receptors, Signal Transduction, Solubility, Staphylococcus aureus}, pubstate = {published}, tppubtype = {article} } BACKGROUND: Two NF-kappaB signaling pathways, Toll and immune deficiency (imd), are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense. METHODOLOGY/PRINCIPAL FINDINGS: In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus), we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response. CONCLUSIONS/SIGNIFICANCE: Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen. |
2010 |
Silverman, Gary A; Whisstock, James C; Bottomley, Stephen P; Huntington, James A; Kaiserman, Dion; Luke, Cliff J; Pak, Stephen C; Reichhart, Jean-Marc; Bird, Phillip I Serpins flex their muscle: I. Putting the clamps on proteolysis in diverse biological systems Article de journal J. Biol. Chem., 285 (32), p. 24299–24305, 2010, ISSN: 1083-351X. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological, Caenorhabditis elegans, Cell Death, Cell Differentiation, Cell Survival, Homeostasis, Humans, Immunity, Innate, M3i, Mice, Models, Phenotype, reichhart, Serpins, Transgenes, transgenic @article{silverman_serpins_2010, title = {Serpins flex their muscle: I. Putting the clamps on proteolysis in diverse biological systems}, author = {Gary A Silverman and James C Whisstock and Stephen P Bottomley and James A Huntington and Dion Kaiserman and Cliff J Luke and Stephen C Pak and Jean-Marc Reichhart and Phillip I Bird}, doi = {10.1074/jbc.R110.112771}, issn = {1083-351X}, year = {2010}, date = {2010-08-01}, journal = {J. Biol. Chem.}, volume = {285}, number = {32}, pages = {24299--24305}, abstract = {Serpins compose the largest superfamily of peptidase inhibitors and are well known as regulators of hemostasis and thrombolysis. Studies using model organisms, from plants to vertebrates, now show that serpins and their unique inhibitory mechanism and conformational flexibility are exploited to control proteolysis in molecular pathways associated with cell survival, development, and host defense. In addition, an increasing number of non-inhibitory serpins are emerging as important elements within a diversity of biological systems by serving as chaperones, hormone transporters, or anti-angiogenic factors.}, keywords = {Animals, Biological, Caenorhabditis elegans, Cell Death, Cell Differentiation, Cell Survival, Homeostasis, Humans, Immunity, Innate, M3i, Mice, Models, Phenotype, reichhart, Serpins, Transgenes, transgenic}, pubstate = {published}, tppubtype = {article} } Serpins compose the largest superfamily of peptidase inhibitors and are well known as regulators of hemostasis and thrombolysis. Studies using model organisms, from plants to vertebrates, now show that serpins and their unique inhibitory mechanism and conformational flexibility are exploited to control proteolysis in molecular pathways associated with cell survival, development, and host defense. In addition, an increasing number of non-inhibitory serpins are emerging as important elements within a diversity of biological systems by serving as chaperones, hormone transporters, or anti-angiogenic factors. |
Whisstock, James C; Silverman, Gary A; Bird, Phillip I; Bottomley, Stephen P; Kaiserman, Dion; Luke, Cliff J; Pak, Stephen C; Reichhart, Jean-Marc; Huntington, James A Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions Article de journal J. Biol. Chem., 285 (32), p. 24307–24312, 2010, ISSN: 1083-351X. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological, Biological Transport, Biophysics, Catalytic Domain, Hormones, Humans, Kinetics, M3i, Models, Peptide Hydrolases, Protein Binding, Protein Conformation, Protein Structure, reichhart, Serpins, Substrate Specificity, Tertiary, Thrombin @article{whisstock_serpins_2010, title = {Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions}, author = {James C Whisstock and Gary A Silverman and Phillip I Bird and Stephen P Bottomley and Dion Kaiserman and Cliff J Luke and Stephen C Pak and Jean-Marc Reichhart and James A Huntington}, doi = {10.1074/jbc.R110.141408}, issn = {1083-351X}, year = {2010}, date = {2010-08-01}, journal = {J. Biol. Chem.}, volume = {285}, number = {32}, pages = {24307--24312}, abstract = {Inhibitory serpins are metastable proteins that undergo a substantial conformational rearrangement to covalently trap target peptidases. The serpin reactive center loop contributes a majority of the interactions that serpins make during the initial binding to target peptidases. However, structural studies on serpin-peptidase complexes reveal a broader set of contacts on the scaffold of inhibitory serpins that have substantial influence on guiding peptidase recognition. Structural and biophysical studies also reveal how aberrant serpin folding can lead to the formation of domain-swapped serpin multimers rather than the monomeric metastable state. Serpin domain swapping may therefore underlie the polymerization events characteristic of the serpinopathies. Finally, recent structural studies reveal how the serpin fold has been adapted for non-inhibitory functions such as hormone binding.}, keywords = {Animals, Biological, Biological Transport, Biophysics, Catalytic Domain, Hormones, Humans, Kinetics, M3i, Models, Peptide Hydrolases, Protein Binding, Protein Conformation, Protein Structure, reichhart, Serpins, Substrate Specificity, Tertiary, Thrombin}, pubstate = {published}, tppubtype = {article} } Inhibitory serpins are metastable proteins that undergo a substantial conformational rearrangement to covalently trap target peptidases. The serpin reactive center loop contributes a majority of the interactions that serpins make during the initial binding to target peptidases. However, structural studies on serpin-peptidase complexes reveal a broader set of contacts on the scaffold of inhibitory serpins that have substantial influence on guiding peptidase recognition. Structural and biophysical studies also reveal how aberrant serpin folding can lead to the formation of domain-swapped serpin multimers rather than the monomeric metastable state. Serpin domain swapping may therefore underlie the polymerization events characteristic of the serpinopathies. Finally, recent structural studies reveal how the serpin fold has been adapted for non-inhibitory functions such as hormone binding. |
Matskevich, Alexey A; Quintin, Jessica; Ferrandon, Dominique The Drosophila PRR GNBP3 assembles effector complexes involved in antifungal defenses independently of its Toll-pathway activation function Article de journal Eur. J. Immunol., 40 (5), p. 1244–1254, 2010, ISSN: 1521-4141. Résumé | Liens | BibTeX | Étiquettes: Agglutination, Animals, Beauveria, Beauveria/immunology, Candida albicans, Candida albicans/immunology, Carrier Proteins, Carrier Proteins/*immunology/pharmacology, Drosophila melanogaster/*immunology/microbiology, Drosophila Proteins/*immunology/pharmacology/physiology, Enzyme Activation, ferrandon, Fungal, Fungi, Fungi/*immunology, Hemolymph, Hemolymph/immunology, M3i, Melanins, Melanins/*physiology, Monophenol Monooxygenase, Monophenol Monooxygenase/physiology, Multiprotein Complexes, Multiprotein Complexes/physiology, Recombinant Fusion Proteins, Recombinant Fusion Proteins/pharmacology, Serpins, Serpins/physiology, Spores, Toll-Like Receptors, Toll-Like Receptors/immunology @article{matskevich_drosophila_2010b, title = {The Drosophila PRR GNBP3 assembles effector complexes involved in antifungal defenses independently of its Toll-pathway activation function}, author = {Alexey A Matskevich and Jessica Quintin and Dominique Ferrandon}, doi = {10.1002/eji.200940164}, issn = {1521-4141}, year = {2010}, date = {2010-05-01}, journal = {Eur. J. Immunol.}, volume = {40}, number = {5}, pages = {1244--1254}, abstract = {The Drosophila Toll-signaling pathway controls the systemic antifungal host response. Gram-negative binding protein 3 (GNBP3), a member of the beta-glucan recognition protein family senses fungal infections and activates this pathway. A second detection system perceives the activity of proteolytic fungal virulence factors and redundantly activates Toll. GNBP3(hades) mutant flies succumb more rapidly to Candida albicans and to entomopathogenic fungal infections than WT flies, despite normal triggering of the Toll pathway via the virulence detection system. These observations suggest that GNBP3 triggers antifungal defenses that are not dependent on activation of the Toll pathway. Here, we show that GNBP3 agglutinates fungal cells. Furthermore, it can activate melanization in a Toll-independent manner. Melanization is likely to be an essential defense against some fungal infections given that the entomopathogenic fungus Beauveria bassiana inhibits the activity of the main melanization enzymes, the phenol oxidases. Finally, we show that GNBP3 assembles "attack complexes", which comprise phenoloxidase and the necrotic serpin. We propose that Drosophila GNBP3 targets fungi immediately at the inception of the infection by bringing effector molecules in direct contact with the invading microorganisms.}, keywords = {Agglutination, Animals, Beauveria, Beauveria/immunology, Candida albicans, Candida albicans/immunology, Carrier Proteins, Carrier Proteins/*immunology/pharmacology, Drosophila melanogaster/*immunology/microbiology, Drosophila Proteins/*immunology/pharmacology/physiology, Enzyme Activation, ferrandon, Fungal, Fungi, Fungi/*immunology, Hemolymph, Hemolymph/immunology, M3i, Melanins, Melanins/*physiology, Monophenol Monooxygenase, Monophenol Monooxygenase/physiology, Multiprotein Complexes, Multiprotein Complexes/physiology, Recombinant Fusion Proteins, Recombinant Fusion Proteins/pharmacology, Serpins, Serpins/physiology, Spores, Toll-Like Receptors, Toll-Like Receptors/immunology}, pubstate = {published}, tppubtype = {article} } The Drosophila Toll-signaling pathway controls the systemic antifungal host response. Gram-negative binding protein 3 (GNBP3), a member of the beta-glucan recognition protein family senses fungal infections and activates this pathway. A second detection system perceives the activity of proteolytic fungal virulence factors and redundantly activates Toll. GNBP3(hades) mutant flies succumb more rapidly to Candida albicans and to entomopathogenic fungal infections than WT flies, despite normal triggering of the Toll pathway via the virulence detection system. These observations suggest that GNBP3 triggers antifungal defenses that are not dependent on activation of the Toll pathway. Here, we show that GNBP3 agglutinates fungal cells. Furthermore, it can activate melanization in a Toll-independent manner. Melanization is likely to be an essential defense against some fungal infections given that the entomopathogenic fungus Beauveria bassiana inhibits the activity of the main melanization enzymes, the phenol oxidases. Finally, we show that GNBP3 assembles "attack complexes", which comprise phenoloxidase and the necrotic serpin. We propose that Drosophila GNBP3 targets fungi immediately at the inception of the infection by bringing effector molecules in direct contact with the invading microorganisms. |
Garcia, Alvaro Baeza; Pierce, Raymond J; Gourbal, Benjamin; Werkmeister, Elisabeth; Colinet, Dominique; Reichhart, Jean-Marc; Dissous, Colette; Coustau, Christine Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni Article de journal PLoS Pathog., 6 (9), p. e1001115, 2010, ISSN: 1553-7374. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western @article{baeza_garcia_involvement_2010, title = {Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni}, author = {Alvaro Baeza Garcia and Raymond J Pierce and Benjamin Gourbal and Elisabeth Werkmeister and Dominique Colinet and Jean-Marc Reichhart and Colette Dissous and Christine Coustau}, doi = {10.1371/journal.ppat.1001115}, issn = {1553-7374}, year = {2010}, date = {2010-01-01}, journal = {PLoS Pathog.}, volume = {6}, number = {9}, pages = {e1001115}, abstract = {We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.}, keywords = {Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western}, pubstate = {published}, tppubtype = {article} } We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions. |
Paquette, Nicholas; Broemer, Meike; Aggarwal, Kamna; Chen, Li; Husson, Marie; Ertürk-Hasdemir, Deniz; Reichhart, Jean-Marc; Meier, Pascal; Silverman, Neal Caspase-mediated cleavage, IAP binding, and ubiquitination: linking three mechanisms crucial for Drosophila NF-kappaB signaling Article de journal Mol. Cell, 37 (2), p. 172–182, 2010, ISSN: 1097-4164. Résumé | Liens | BibTeX | Étiquettes: Alleles, Amino Acid Motifs, Animals, Biological, Caspases, Inhibitor of Apoptosis Proteins, M3i, MAP Kinase Kinase Kinases, Models, NF-kappa B, reichhart, Sequence Alignment, Signal Transduction, Ubiquitin-Protein Ligases, Ubiquitination @article{paquette_caspase-mediated_2010, title = {Caspase-mediated cleavage, IAP binding, and ubiquitination: linking three mechanisms crucial for Drosophila NF-kappaB signaling}, author = {Nicholas Paquette and Meike Broemer and Kamna Aggarwal and Li Chen and Marie Husson and Deniz Ertürk-Hasdemir and Jean-Marc Reichhart and Pascal Meier and Neal Silverman}, doi = {10.1016/j.molcel.2009.12.036}, issn = {1097-4164}, year = {2010}, date = {2010-01-01}, journal = {Mol. Cell}, volume = {37}, number = {2}, pages = {172--182}, abstract = {Innate immune responses are critical for the immediate protection against microbial infection. In Drosophila, infection leads to the rapid and robust production of antimicrobial peptides through two NF-kappaB signaling pathways-IMD and Toll. The IMD pathway is triggered by DAP-type peptidoglycan, common to most Gram-negative bacteria. Signaling downstream from the peptidoglycan receptors is thought to involve K63 ubiquitination and caspase-mediated cleavage, but the molecular mechanisms remain obscure. We now show that PGN stimulation causes caspase-mediated cleavage of the imd protein, exposing a highly conserved IAP-binding motif (IBM) at its neo-N terminus. A functional IBM is required for the association of cleaved IMD with the ubiquitin E3-ligase DIAP2. Through its association with DIAP2, IMD is rapidly conjugated with K63-linked polyubiquitin chains. These results mechanistically connect caspase-mediated cleavage and K63 ubiquitination in immune-induced NF-kappaB signaling.}, keywords = {Alleles, Amino Acid Motifs, Animals, Biological, Caspases, Inhibitor of Apoptosis Proteins, M3i, MAP Kinase Kinase Kinases, Models, NF-kappa B, reichhart, Sequence Alignment, Signal Transduction, Ubiquitin-Protein Ligases, Ubiquitination}, pubstate = {published}, tppubtype = {article} } Innate immune responses are critical for the immediate protection against microbial infection. In Drosophila, infection leads to the rapid and robust production of antimicrobial peptides through two NF-kappaB signaling pathways-IMD and Toll. The IMD pathway is triggered by DAP-type peptidoglycan, common to most Gram-negative bacteria. Signaling downstream from the peptidoglycan receptors is thought to involve K63 ubiquitination and caspase-mediated cleavage, but the molecular mechanisms remain obscure. We now show that PGN stimulation causes caspase-mediated cleavage of the imd protein, exposing a highly conserved IAP-binding motif (IBM) at its neo-N terminus. A functional IBM is required for the association of cleaved IMD with the ubiquitin E3-ligase DIAP2. Through its association with DIAP2, IMD is rapidly conjugated with K63-linked polyubiquitin chains. These results mechanistically connect caspase-mediated cleavage and K63 ubiquitination in immune-induced NF-kappaB signaling. |
Pospisilik, Andrew J; Schramek, Daniel; Schnidar, Harald; Cronin, Shane J F; Nehme, Nadine T; Zhang, Xiaoyun; Knauf, Claude; Cani, Patrice D; Aumayr, Karin; Todoric, Jelena; Bayer, Martina; Haschemi, Arvand; Puviindran, Vijitha; Tar, Krisztina; Orthofer, Michael; Neely, Gregory G; Dietzl, Georg; Manoukian, Armen; Funovics, Martin; Prager, Gerhard; Wagner, Oswald; Ferrandon, Dominique; Aberger, Fritz; Hui, Chi-chung; Esterbauer, Harald; Penninger, Josef M Drosophila genome-wide obesity screen reveals hedgehog as a determinant of brown versus white adipose cell fate Article de journal Cell, 140 (1), p. 148–160, 2010, ISSN: 1097-4172. Résumé | Liens | BibTeX | Étiquettes: Adipocytes, Adipogenesis, Animals, Brown, Brown/metabolism, Cyclic AMP, Cyclic AMP/metabolism, Drosophila Proteins/*metabolism, ferrandon, Glucocorticoids, Glucocorticoids/metabolism, Hedgehog Proteins, Hedgehog Proteins/*metabolism, Humans, Knockout, M3i, Mice, Muscle Cells, Muscle Cells/metabolism, Obesity, Obesity/*genetics, Repressor Proteins, Repressor Proteins/genetics, White, White/metabolism @article{pospisilik_drosophila_2010b, title = {Drosophila genome-wide obesity screen reveals hedgehog as a determinant of brown versus white adipose cell fate}, author = {Andrew J Pospisilik and Daniel Schramek and Harald Schnidar and Shane J F Cronin and Nadine T Nehme and Xiaoyun Zhang and Claude Knauf and Patrice D Cani and Karin Aumayr and Jelena Todoric and Martina Bayer and Arvand Haschemi and Vijitha Puviindran and Krisztina Tar and Michael Orthofer and Gregory G Neely and Georg Dietzl and Armen Manoukian and Martin Funovics and Gerhard Prager and Oswald Wagner and Dominique Ferrandon and Fritz Aberger and Chi-chung Hui and Harald Esterbauer and Josef M Penninger}, doi = {10.1016/j.cell.2009.12.027}, issn = {1097-4172}, year = {2010}, date = {2010-01-01}, journal = {Cell}, volume = {140}, number = {1}, pages = {148--160}, abstract = {Over 1 billion people are estimated to be overweight, placing them at risk for diabetes, cardiovascular disease, and cancer. We performed a systems-level genetic dissection of adiposity regulation using genome-wide RNAi screening in adult Drosophila. As a follow-up, the resulting approximately 500 candidate obesity genes were functionally classified using muscle-, oenocyte-, fat-body-, and neuronal-specific knockdown in vivo and revealed hedgehog signaling as the top-scoring fat-body-specific pathway. To extrapolate these findings into mammals, we generated fat-specific hedgehog-activation mutant mice. Intriguingly, these mice displayed near total loss of white, but not brown, fat compartments. Mechanistically, activation of hedgehog signaling irreversibly blocked differentiation of white adipocytes through direct, coordinate modulation of early adipogenic factors. These findings identify a role for hedgehog signaling in white/brown adipocyte determination and link in vivo RNAi-based scanning of the Drosophila genome to regulation of adipocyte cell fate in mammals.}, keywords = {Adipocytes, Adipogenesis, Animals, Brown, Brown/metabolism, Cyclic AMP, Cyclic AMP/metabolism, Drosophila Proteins/*metabolism, ferrandon, Glucocorticoids, Glucocorticoids/metabolism, Hedgehog Proteins, Hedgehog Proteins/*metabolism, Humans, Knockout, M3i, Mice, Muscle Cells, Muscle Cells/metabolism, Obesity, Obesity/*genetics, Repressor Proteins, Repressor Proteins/genetics, White, White/metabolism}, pubstate = {published}, tppubtype = {article} } Over 1 billion people are estimated to be overweight, placing them at risk for diabetes, cardiovascular disease, and cancer. We performed a systems-level genetic dissection of adiposity regulation using genome-wide RNAi screening in adult Drosophila. As a follow-up, the resulting approximately 500 candidate obesity genes were functionally classified using muscle-, oenocyte-, fat-body-, and neuronal-specific knockdown in vivo and revealed hedgehog signaling as the top-scoring fat-body-specific pathway. To extrapolate these findings into mammals, we generated fat-specific hedgehog-activation mutant mice. Intriguingly, these mice displayed near total loss of white, but not brown, fat compartments. Mechanistically, activation of hedgehog signaling irreversibly blocked differentiation of white adipocytes through direct, coordinate modulation of early adipogenic factors. These findings identify a role for hedgehog signaling in white/brown adipocyte determination and link in vivo RNAi-based scanning of the Drosophila genome to regulation of adipocyte cell fate in mammals. |
2009 |
Shia, Alice K H; Glittenberg, Marcus; Thompson, Gavin; Weber, Alexander N R; Reichhart, Jean-Marc; Ligoxygakis, Petros Toll-dependent antimicrobial responses in Drosophila larval fat body require Spätzle secreted by haemocytes Article de journal J. Cell. Sci., 122 (Pt 24), p. 4505–4515, 2009, ISSN: 1477-9137. Résumé | Liens | BibTeX | Étiquettes: Animals, Enterococcus faecalis, Escherichia coli, Fat Body, Hemocytes, Larva, M3i, reichhart, Toll-Like Receptors @article{shia_toll-dependent_2009, title = {Toll-dependent antimicrobial responses in Drosophila larval fat body require Spätzle secreted by haemocytes}, author = {Alice K H Shia and Marcus Glittenberg and Gavin Thompson and Alexander N R Weber and Jean-Marc Reichhart and Petros Ligoxygakis}, doi = {10.1242/jcs.049155}, issn = {1477-9137}, year = {2009}, date = {2009-12-01}, journal = {J. Cell. Sci.}, volume = {122}, number = {Pt 24}, pages = {4505--4515}, abstract = {In Drosophila, the humoral response characterised by the synthesis of antimicrobial peptides (AMPs) in the fat body (the equivalent of the mammalian liver) and the cellular response mediated by haemocytes (blood cells) engaged in phagocytosis represent two major reactions that counter pathogens. Although considerable analysis has permitted the elucidation of mechanisms pertaining to the two responses individually, the mechanism of their coordination has been unclear. To characterise the signals with which infection might be communicated between blood cells and fat body, we ablated circulating haemocytes and defined the parameters of AMP gene activation in larvae. We found that targeted ablation of blood cells influenced the levels of AMP gene expression in the fat body following both septic injury and oral infection. Expression of the AMP gene drosomycin (a Toll target) was blocked when expression of the Toll ligand Spätzle was knocked down in haemocytes. These results show that in larvae, integration of the two responses in a systemic reaction depend on the production of a cytokine (spz), a process that strongly parallels the mammalian immune response.}, keywords = {Animals, Enterococcus faecalis, Escherichia coli, Fat Body, Hemocytes, Larva, M3i, reichhart, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } In Drosophila, the humoral response characterised by the synthesis of antimicrobial peptides (AMPs) in the fat body (the equivalent of the mammalian liver) and the cellular response mediated by haemocytes (blood cells) engaged in phagocytosis represent two major reactions that counter pathogens. Although considerable analysis has permitted the elucidation of mechanisms pertaining to the two responses individually, the mechanism of their coordination has been unclear. To characterise the signals with which infection might be communicated between blood cells and fat body, we ablated circulating haemocytes and defined the parameters of AMP gene activation in larvae. We found that targeted ablation of blood cells influenced the levels of AMP gene expression in the fat body following both septic injury and oral infection. Expression of the AMP gene drosomycin (a Toll target) was blocked when expression of the Toll ligand Spätzle was knocked down in haemocytes. These results show that in larvae, integration of the two responses in a systemic reaction depend on the production of a cytokine (spz), a process that strongly parallels the mammalian immune response. |
Hetru, Charles; Hoffmann, Jules A NF-kappaB in the immune response of Drosophila Article de journal Cold Spring Harb Perspect Biol, 1 (6), p. a000232, 2009, ISSN: 1943-0264. Résumé | Liens | BibTeX | Étiquettes: Animals, bacteria, Fungi, Gene Expression Regulation, hoffmann, M3i, NF-kappa B @article{hetru_nf-kappab_2009, title = {NF-kappaB in the immune response of Drosophila}, author = {Charles Hetru and Jules A Hoffmann}, doi = {10.1101/cshperspect.a000232}, issn = {1943-0264}, year = {2009}, date = {2009-12-01}, journal = {Cold Spring Harb Perspect Biol}, volume = {1}, number = {6}, pages = {a000232}, abstract = {The nuclear factor kappaB (NF-kappaB) pathways play a major role in Drosophila host defense. Two recognition and signaling cascades control this immune response. The Toll pathway is activated by Gram-positive bacteria and by fungi, whereas the immune deficiency (Imd) pathway responds to Gram-negative bacterial infection. The basic mechanisms of recognition of these various types of microbial infections by the adult fly are now globally understood. Even though some elements are missing in the intracellular pathways, numerous proteins and interactions have been identified. In this article, we present a general picture of the immune functions of NF-kappaB in Drosophila with all the partners involved in recognition and in the signaling cascades.}, keywords = {Animals, bacteria, Fungi, Gene Expression Regulation, hoffmann, M3i, NF-kappa B}, pubstate = {published}, tppubtype = {article} } The nuclear factor kappaB (NF-kappaB) pathways play a major role in Drosophila host defense. Two recognition and signaling cascades control this immune response. The Toll pathway is activated by Gram-positive bacteria and by fungi, whereas the immune deficiency (Imd) pathway responds to Gram-negative bacterial infection. The basic mechanisms of recognition of these various types of microbial infections by the adult fly are now globally understood. Even though some elements are missing in the intracellular pathways, numerous proteins and interactions have been identified. In this article, we present a general picture of the immune functions of NF-kappaB in Drosophila with all the partners involved in recognition and in the signaling cascades. |
Mishima, Yumiko; Quintin, Jessica; Aimanianda, Vishukumar; Kellenberger, Christine; Coste, Franck; Clavaud, Cecile; Hetru, Charles; Hoffmann, Jules A; Latgé, Jean-Paul; Ferrandon, Dominique; Roussel, Alain The N-terminal domain of Drosophila Gram-negative binding protein 3 (GNBP3) defines a novel family of fungal pattern recognition receptors Article de journal J. Biol. Chem., 284 (42), p. 28687–28697, 2009, ISSN: 1083-351X. Résumé | Liens | BibTeX | Étiquettes: Animals, beta-Glucans, Bombyx, Carrier Proteins, Crystallography, ferrandon, Fungal Proteins, Hemolymph, hoffmann, ligands, M3i, Molecular Conformation, Mutagenesis, Polysaccharides, Protein Structure, Secondary, Tertiary, X-Ray @article{mishima_n-terminal_2009, title = {The N-terminal domain of Drosophila Gram-negative binding protein 3 (GNBP3) defines a novel family of fungal pattern recognition receptors}, author = {Yumiko Mishima and Jessica Quintin and Vishukumar Aimanianda and Christine Kellenberger and Franck Coste and Cecile Clavaud and Charles Hetru and Jules A Hoffmann and Jean-Paul Latgé and Dominique Ferrandon and Alain Roussel}, doi = {10.1074/jbc.M109.034587}, issn = {1083-351X}, year = {2009}, date = {2009-10-01}, journal = {J. Biol. Chem.}, volume = {284}, number = {42}, pages = {28687--28697}, abstract = {Gram-negative binding protein 3 (GNBP3), a pattern recognition receptor that circulates in the hemolymph of Drosophila, is responsible for sensing fungal infection and triggering Toll pathway activation. Here, we report that GNBP3 N-terminal domain binds to fungi upon identifying long chains of beta-1,3-glucans in the fungal cell wall as a major ligand. Interestingly, this domain fails to interact strongly with short oligosaccharides. The crystal structure of GNBP3-Nter reveals an immunoglobulin-like fold in which the glucan binding site is masked by a loop that is highly conserved among glucan-binding proteins identified in several insect orders. Structure-based mutagenesis experiments reveal an essential role for this occluding loop in discriminating between short and long polysaccharides. The displacement of the occluding loop is necessary for binding and could explain the specificity of the interaction with long chain structured polysaccharides. This represents a novel mechanism for beta-glucan recognition.}, keywords = {Animals, beta-Glucans, Bombyx, Carrier Proteins, Crystallography, ferrandon, Fungal Proteins, Hemolymph, hoffmann, ligands, M3i, Molecular Conformation, Mutagenesis, Polysaccharides, Protein Structure, Secondary, Tertiary, X-Ray}, pubstate = {published}, tppubtype = {article} } Gram-negative binding protein 3 (GNBP3), a pattern recognition receptor that circulates in the hemolymph of Drosophila, is responsible for sensing fungal infection and triggering Toll pathway activation. Here, we report that GNBP3 N-terminal domain binds to fungi upon identifying long chains of beta-1,3-glucans in the fungal cell wall as a major ligand. Interestingly, this domain fails to interact strongly with short oligosaccharides. The crystal structure of GNBP3-Nter reveals an immunoglobulin-like fold in which the glucan binding site is masked by a loop that is highly conserved among glucan-binding proteins identified in several insect orders. Structure-based mutagenesis experiments reveal an essential role for this occluding loop in discriminating between short and long polysaccharides. The displacement of the occluding loop is necessary for binding and could explain the specificity of the interaction with long chain structured polysaccharides. This represents a novel mechanism for beta-glucan recognition. |
Ferrandon, Dominique Host tolerance versus resistance and microbial virulence in the host-pathogen equation Article de journal Cell Host Microbe, 6 (3), p. 203–205, 2009, ISSN: 1934-6069. Résumé | Liens | BibTeX | Étiquettes: Animals, ferrandon, Host-Pathogen Interactions, Immune Tolerance, M3i, Salmonella typhimurium, Virulence @article{ferrandon_host_2009b, title = {Host tolerance versus resistance and microbial virulence in the host-pathogen equation}, author = {Dominique Ferrandon}, doi = {10.1016/j.chom.2009.08.010}, issn = {1934-6069}, year = {2009}, date = {2009-09-01}, journal = {Cell Host Microbe}, volume = {6}, number = {3}, pages = {203--205}, abstract = {To deal with an infection, the organism resorts to nonmutually exclusive strategies: resistance, that is, neutralization or destruction of the pathogen; or tolerance, the ability to withstand damages inflicted by the pathogen or by host defense. In this issue of Cell Host & Microbe, Shinzawa et al. (2009) identify p38-mediated phagocytic encapsulation as a potential tolerance mechanism.}, keywords = {Animals, ferrandon, Host-Pathogen Interactions, Immune Tolerance, M3i, Salmonella typhimurium, Virulence}, pubstate = {published}, tppubtype = {article} } To deal with an infection, the organism resorts to nonmutually exclusive strategies: resistance, that is, neutralization or destruction of the pathogen; or tolerance, the ability to withstand damages inflicted by the pathogen or by host defense. In this issue of Cell Host & Microbe, Shinzawa et al. (2009) identify p38-mediated phagocytic encapsulation as a potential tolerance mechanism. |
Fraiture, Malou; Baxter, Richard H G; Steinert, Stefanie; Chelliah, Yogarany; Frolet, Cécile; Quispe-Tintaya, Wilber; Hoffmann, Jules A; Blandin, Stéphanie A; Levashina, Elena A Two mosquito LRR proteins function as complement control factors in the TEP1-mediated killing of Plasmodium Article de journal Cell Host Microbe, 5 (3), p. 273–284, 2009, ISSN: 1934-6069. Résumé | Liens | BibTeX | Étiquettes: Animals, Anopheles, APL1, Biological, blandin, Complement System Proteins, Hemolymph, hoffmann, Immunologic Factors, LRIM1, M3i, Models, Plasmodium, Protein Binding, Proteins, TEP1 @article{fraiture_two_2009, title = {Two mosquito LRR proteins function as complement control factors in the TEP1-mediated killing of Plasmodium}, author = {Malou Fraiture and Richard H G Baxter and Stefanie Steinert and Yogarany Chelliah and Cécile Frolet and Wilber Quispe-Tintaya and Jules A Hoffmann and Stéphanie A Blandin and Elena A Levashina}, doi = {10.1016/j.chom.2009.01.005}, issn = {1934-6069}, year = {2009}, date = {2009-03-01}, journal = {Cell Host Microbe}, volume = {5}, number = {3}, pages = {273--284}, abstract = {Plasmodium development within Anopheles mosquitoes is a vulnerable step in the parasite transmission cycle, and targeting this step represents a promising strategy for malaria control. The thioester-containing complement-like protein TEP1 and two leucine-rich repeat (LRR) proteins, LRIM1 and APL1, have been identified as major mosquito factors that regulate parasite loads. Here, we show that LRIM1 and APL1 are required for binding of TEP1 to parasites. RNAi silencing of the LRR-encoding genes results in deposition of TEP1 on Anopheles tissues, thereby depleting TEP1 from circulation in the hemolymph and impeding its binding to Plasmodium. LRIM1 and APL1 not only stabilize circulating TEP1, they also stabilize each other prior to their interaction with TEP1. Our results indicate that three major antiparasitic factors in mosquitoes jointly function as a complement-like system in parasite killing, and they reveal a role for LRR proteins as complement control factors.}, keywords = {Animals, Anopheles, APL1, Biological, blandin, Complement System Proteins, Hemolymph, hoffmann, Immunologic Factors, LRIM1, M3i, Models, Plasmodium, Protein Binding, Proteins, TEP1}, pubstate = {published}, tppubtype = {article} } Plasmodium development within Anopheles mosquitoes is a vulnerable step in the parasite transmission cycle, and targeting this step represents a promising strategy for malaria control. The thioester-containing complement-like protein TEP1 and two leucine-rich repeat (LRR) proteins, LRIM1 and APL1, have been identified as major mosquito factors that regulate parasite loads. Here, we show that LRIM1 and APL1 are required for binding of TEP1 to parasites. RNAi silencing of the LRR-encoding genes results in deposition of TEP1 on Anopheles tissues, thereby depleting TEP1 from circulation in the hemolymph and impeding its binding to Plasmodium. LRIM1 and APL1 not only stabilize circulating TEP1, they also stabilize each other prior to their interaction with TEP1. Our results indicate that three major antiparasitic factors in mosquitoes jointly function as a complement-like system in parasite killing, and they reveal a role for LRR proteins as complement control factors. |
Kemp, Cordula; Imler, Jean-Luc Antiviral immunity in drosophila Article de journal Current Opinion in Immunology, 21 (1), p. 3–9, 2009, ISSN: 1879-0372. Résumé | Liens | BibTeX | Étiquettes: Animals, Argonaute Proteins, Caspases, DEAD-box RNA Helicases, Evolution, Gene Expression Regulation, Host-Pathogen Interactions, imler, M3i, Membrane Proteins, Molecular, Nuclear Proteins, Ribonuclease III, RNA, RNA Helicases, RNA Interference, RNA Virus Infections, RNA Viruses, RNA-Induced Silencing Complex, Viral, Virulence @article{kemp_antiviral_2009, title = {Antiviral immunity in drosophila}, author = {Cordula Kemp and Jean-Luc Imler}, doi = {10.1016/j.coi.2009.01.007}, issn = {1879-0372}, year = {2009}, date = {2009-02-01}, journal = {Current Opinion in Immunology}, volume = {21}, number = {1}, pages = {3--9}, abstract = {Genetic analysis of the drosophila antiviral response indicates that RNA interference plays a major role. This contrasts with the situation in mammals, where interferon-induced responses mediate innate antiviral host-defense. An inducible response also contributes to antiviral immunity in drosophila, and similarities in the sensing and signaling of viral infection are becoming apparent between drosophila and mammals. In particular, DExD/H box helicases appear to play a crucial role in the cytosolic detection of viral RNAs in flies and mammals.}, keywords = {Animals, Argonaute Proteins, Caspases, DEAD-box RNA Helicases, Evolution, Gene Expression Regulation, Host-Pathogen Interactions, imler, M3i, Membrane Proteins, Molecular, Nuclear Proteins, Ribonuclease III, RNA, RNA Helicases, RNA Interference, RNA Virus Infections, RNA Viruses, RNA-Induced Silencing Complex, Viral, Virulence}, pubstate = {published}, tppubtype = {article} } Genetic analysis of the drosophila antiviral response indicates that RNA interference plays a major role. This contrasts with the situation in mammals, where interferon-induced responses mediate innate antiviral host-defense. An inducible response also contributes to antiviral immunity in drosophila, and similarities in the sensing and signaling of viral infection are becoming apparent between drosophila and mammals. In particular, DExD/H box helicases appear to play a crucial role in the cytosolic detection of viral RNAs in flies and mammals. |
Berry, Bassam; Deddouche, Safia; Kirschner, Doris; Imler, Jean-Luc; Antoniewski, Christophe Viral suppressors of RNA silencing hinder exogenous and endogenous small RNA pathways in Drosophila Article de journal PloS One, 4 (6), p. e5866, 2009, ISSN: 1932-6203. Résumé | Liens | BibTeX | Étiquettes: Animals, Antiviral Agents, Crosses, Double-Stranded, Gene Silencing, Genetic, Genetically Modified, Heterozygote, imler, Invertebrate, M3i, Photoreceptor Cells, Reverse Transcriptase Polymerase Chain Reaction, RNA, RNA Interference, Transgenes @article{berry_viral_2009, title = {Viral suppressors of RNA silencing hinder exogenous and endogenous small RNA pathways in Drosophila}, author = {Bassam Berry and Safia Deddouche and Doris Kirschner and Jean-Luc Imler and Christophe Antoniewski}, doi = {10.1371/journal.pone.0005866}, issn = {1932-6203}, year = {2009}, date = {2009-01-01}, journal = {PloS One}, volume = {4}, number = {6}, pages = {e5866}, abstract = {BACKGROUND: In plants and insects, RNA interference (RNAi) is the main responder against viruses and shapes the basis of antiviral immunity. Viruses counter this defense by expressing viral suppressors of RNAi (VSRs). While VSRs in Drosophila melanogaster were shown to inhibit RNAi through different modes of action, whether they act on other silencing pathways remained unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that expression of various plant and insect VSRs in transgenic flies does not perturb the Drosophila microRNA (miRNA) pathway; but in contrast, inhibits antiviral RNAi and the RNA silencing response triggered by inverted repeat transcripts, and injection of dsRNA or siRNA. Strikingly, these VSRs also suppressed transposon silencing by endogenous siRNAs (endo-siRNAs). CONCLUSIONS/SIGNIFICANCE: Our findings identify VSRs as tools to unravel small RNA pathways in insects and suggest a cosuppression of antiviral RNAi and endo-siRNA silencing by viruses during fly infections.}, keywords = {Animals, Antiviral Agents, Crosses, Double-Stranded, Gene Silencing, Genetic, Genetically Modified, Heterozygote, imler, Invertebrate, M3i, Photoreceptor Cells, Reverse Transcriptase Polymerase Chain Reaction, RNA, RNA Interference, Transgenes}, pubstate = {published}, tppubtype = {article} } BACKGROUND: In plants and insects, RNA interference (RNAi) is the main responder against viruses and shapes the basis of antiviral immunity. Viruses counter this defense by expressing viral suppressors of RNAi (VSRs). While VSRs in Drosophila melanogaster were shown to inhibit RNAi through different modes of action, whether they act on other silencing pathways remained unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that expression of various plant and insect VSRs in transgenic flies does not perturb the Drosophila microRNA (miRNA) pathway; but in contrast, inhibits antiviral RNAi and the RNA silencing response triggered by inverted repeat transcripts, and injection of dsRNA or siRNA. Strikingly, these VSRs also suppressed transposon silencing by endogenous siRNAs (endo-siRNAs). CONCLUSIONS/SIGNIFICANCE: Our findings identify VSRs as tools to unravel small RNA pathways in insects and suggest a cosuppression of antiviral RNAi and endo-siRNA silencing by viruses during fly infections. |
Garrett, Matthew; Fullaondo, Ane; Troxler, Laurent; Micklem, Gos; Gubb, David Identification and analysis of serpin-family genes by homology and synteny across the 12 sequenced Drosophilid genomes Article de journal BMC Genomics, 10 , p. 489, 2009, ISSN: 1471-2164. Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, Comparative Genomic Hybridization, Conserved Sequence, DNA, Drosophilidae, Evolution, Genome, Insect, Molecular, Multigene Family, Sequence Alignment, Sequence Analysis, Serpins, Synteny @article{garrett_identification_2009, title = {Identification and analysis of serpin-family genes by homology and synteny across the 12 sequenced Drosophilid genomes}, author = {Matthew Garrett and Ane Fullaondo and Laurent Troxler and Gos Micklem and David Gubb}, doi = {10.1186/1471-2164-10-489}, issn = {1471-2164}, year = {2009}, date = {2009-01-01}, journal = {BMC Genomics}, volume = {10}, pages = {489}, abstract = {BACKGROUND: The Drosophila melanogaster genome contains 29 serpin genes, 12 as single transcripts and 17 within 6 gene clusters. Many of these serpins have a conserved "hinge" motif characteristic of active proteinase inhibitors. However, a substantial proportion (42%) lacks this motif and represents non-inhibitory serpin-fold proteins of unknown function. Currently, it is not known whether orthologous, inhibitory serpin genes retain the same target proteinase specificity within the Drosophilid lineage, nor whether they give rise to non-inhibitory serpin-fold proteins or other, more diverged, proteins. RESULTS: We collated 188 orthologues to the D. melanogaster serpins from the other 11 Drosophilid genomes and used synteny to find further family members, raising the total to 226, or 71% of the number of orthologues expected assuming complete conservation across all 12 Drosophilid species. In general the sequence constraints on the serpin-fold itself are loose. The critical Reactive Centre Loop (RCL) sequence, including the target proteinase cleavage site, is strongly conserved in inhibitory serpins, although there are 3 exceptional sets of orthologues in which the evolutionary constraints are looser. Conversely, the RCL of non-inhibitory serpin orthologues is less conserved, with 3 exceptions that presumably bind to conserved partner molecules. We derive a consensus hinge motif, for Drosophilid inhibitory serpins, which differs somewhat from that of the vertebrate consensus. Three gene clusters appear to have originated in the melanogaster subgroup, Spn28D, Spn77B and Spn88E, each containing one inhibitory serpin orthologue that is present in all Drosophilids. In addition, the Spn100A transcript appears to represent a novel serpin-derived fold. CONCLUSION: In general, inhibitory serpins rarely change their range of proteinase targets, except by a duplication/divergence mechanism. Non-inhibitory serpins appear to derive from inhibitory serpins, but not the reverse. The conservation of different family members varied widely across the 12 sequenced Drosophilid genomes. An approach considering synteny as well as homology was important to find the largest set of orthologues.}, keywords = {Animals, bioinformatic, Comparative Genomic Hybridization, Conserved Sequence, DNA, Drosophilidae, Evolution, Genome, Insect, Molecular, Multigene Family, Sequence Alignment, Sequence Analysis, Serpins, Synteny}, pubstate = {published}, tppubtype = {article} } BACKGROUND: The Drosophila melanogaster genome contains 29 serpin genes, 12 as single transcripts and 17 within 6 gene clusters. Many of these serpins have a conserved "hinge" motif characteristic of active proteinase inhibitors. However, a substantial proportion (42%) lacks this motif and represents non-inhibitory serpin-fold proteins of unknown function. Currently, it is not known whether orthologous, inhibitory serpin genes retain the same target proteinase specificity within the Drosophilid lineage, nor whether they give rise to non-inhibitory serpin-fold proteins or other, more diverged, proteins. RESULTS: We collated 188 orthologues to the D. melanogaster serpins from the other 11 Drosophilid genomes and used synteny to find further family members, raising the total to 226, or 71% of the number of orthologues expected assuming complete conservation across all 12 Drosophilid species. In general the sequence constraints on the serpin-fold itself are loose. The critical Reactive Centre Loop (RCL) sequence, including the target proteinase cleavage site, is strongly conserved in inhibitory serpins, although there are 3 exceptional sets of orthologues in which the evolutionary constraints are looser. Conversely, the RCL of non-inhibitory serpin orthologues is less conserved, with 3 exceptions that presumably bind to conserved partner molecules. We derive a consensus hinge motif, for Drosophilid inhibitory serpins, which differs somewhat from that of the vertebrate consensus. Three gene clusters appear to have originated in the melanogaster subgroup, Spn28D, Spn77B and Spn88E, each containing one inhibitory serpin orthologue that is present in all Drosophilids. In addition, the Spn100A transcript appears to represent a novel serpin-derived fold. CONCLUSION: In general, inhibitory serpins rarely change their range of proteinase targets, except by a duplication/divergence mechanism. Non-inhibitory serpins appear to derive from inhibitory serpins, but not the reverse. The conservation of different family members varied widely across the 12 sequenced Drosophilid genomes. An approach considering synteny as well as homology was important to find the largest set of orthologues. |