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2014 |
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. |
2013 |
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. |
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. |
2012 |
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. |
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 |
Boyer, Laurent; Magoc, Lorin; Dejardin, Stephanie; Cappillino, Michael; Paquette, Nicholas; Hinault, Charlotte; Charriere, Guillaume M; Ip, Eddie W K; Fracchia, Shannon; Hennessy, Elizabeth; Erturk-Hasdemir, Deniz; Reichhart, Jean-Marc; Silverman, Neal; Lacy-Hulbert, Adam; Stuart, Lynda M Pathogen-derived effectors trigger protective immunity via activation of the Rac2 enzyme and the IMD or Rip kinase signaling pathway Article de journal Immunity, 35 (4), p. 536–549, 2011, ISSN: 1097-4180. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Enzyme Activation, HEK293 Cells, Humans, M3i, rac GTP-Binding Proteins, Receptor-Interacting Protein Serine-Threonine Kinases, reichhart, Signal Transducing, Signal Transduction @article{boyer_pathogen-derived_2011, title = {Pathogen-derived effectors trigger protective immunity via activation of the Rac2 enzyme and the IMD or Rip kinase signaling pathway}, author = {Laurent Boyer and Lorin Magoc and Stephanie Dejardin and Michael Cappillino and Nicholas Paquette and Charlotte Hinault and Guillaume M Charriere and Eddie W K Ip and Shannon Fracchia and Elizabeth Hennessy and Deniz Erturk-Hasdemir and Jean-Marc Reichhart and Neal Silverman and Adam Lacy-Hulbert and Lynda M Stuart}, doi = {10.1016/j.immuni.2011.08.015}, issn = {1097-4180}, year = {2011}, date = {2011-10-01}, journal = {Immunity}, volume = {35}, number = {4}, pages = {536--549}, abstract = {Although infections with virulent pathogens often induce a strong inflammatory reaction, what drives the increased immune response to pathogens compared to nonpathogenic microbes is poorly understood. One possibility is that the immune system senses the level of threat from a microorganism and augments the response accordingly. Here, focusing on cytotoxic necrotizing factor 1 (CNF1), an Escherichia coli-derived effector molecule, we showed the host indirectly sensed the pathogen by monitoring for the effector that modified RhoGTPases. CNF1 modified Rac2, which then interacted with the innate immune adaptors IMD and Rip1-Rip2 in flies and mammalian cells, respectively, to drive an immune response. This response was protective and increased the ability of the host to restrict pathogen growth, thus defining a mechanism of effector-triggered immunity that contributes to how metazoans defend against microbes with pathogenic potential.}, keywords = {Adaptor Proteins, Enzyme Activation, HEK293 Cells, Humans, M3i, rac GTP-Binding Proteins, Receptor-Interacting Protein Serine-Threonine Kinases, reichhart, Signal Transducing, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Although infections with virulent pathogens often induce a strong inflammatory reaction, what drives the increased immune response to pathogens compared to nonpathogenic microbes is poorly understood. One possibility is that the immune system senses the level of threat from a microorganism and augments the response accordingly. Here, focusing on cytotoxic necrotizing factor 1 (CNF1), an Escherichia coli-derived effector molecule, we showed the host indirectly sensed the pathogen by monitoring for the effector that modified RhoGTPases. CNF1 modified Rac2, which then interacted with the innate immune adaptors IMD and Rip1-Rip2 in flies and mammalian cells, respectively, to drive an immune response. This response was protective and increased the ability of the host to restrict pathogen growth, thus defining a mechanism of effector-triggered immunity that contributes to how metazoans defend against microbes with pathogenic potential. |
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. |
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. |
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 |
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. |
2009 |
Cronin, Shane J F; Nehme, Nadine T; Limmer, Stefanie; Liegeois, Samuel; Pospisilik, Andrew J; Schramek, Daniel; Leibbrandt, Andreas; de Simoes, Ricardo Matos; Gruber, Susanne; Puc, Urszula; Ebersberger, Ingo; Zoranovic, Tamara; Neely, Gregory G; von Haeseler, Arndt; Ferrandon, Dominique; Penninger, Josef M Genome-wide RNAi screen identifies genes involved in intestinal pathogenic bacterial infection Article de journal Science, 325 (5938), p. 340–343, 2009, ISSN: 1095-9203. Résumé | Liens | BibTeX | Étiquettes: *Genome, *RNA Interference, Animal, Animals, Cell Proliferation, Drosophila melanogaster/*genetics/immunology/*microbiology, Drosophila Proteins/genetics/metabolism, Epithelial Cells, Epithelial Cells/cytology/physiology, ferrandon, Genetically Modified, Genome, Hemocytes, Hemocytes/immunology/metabolism/microbiology, Homeostasis, Immunity, Innate, Innate/*genetics, Insect, Intestinal Mucosa, Intestinal Mucosa/cytology/immunology/metabolism/microbiology, Janus Kinases, Janus Kinases/genetics/metabolism, M3i, Models, RNA Interference, Serratia Infections, Serratia Infections/genetics/*immunology/microbiology, Serratia marcescens, Serratia marcescens/*immunology/physiology, Signal Transduction, STAT Transcription Factors, STAT Transcription Factors/genetics/metabolism, Stem Cells, Stem Cells/cytology/physiology @article{cronin_genome-wide_2009b, title = {Genome-wide RNAi screen identifies genes involved in intestinal pathogenic bacterial infection}, author = {Shane J F Cronin and Nadine T Nehme and Stefanie Limmer and Samuel Liegeois and Andrew J Pospisilik and Daniel Schramek and Andreas Leibbrandt and Ricardo Matos de Simoes and Susanne Gruber and Urszula Puc and Ingo Ebersberger and Tamara Zoranovic and Gregory G Neely and Arndt von Haeseler and Dominique Ferrandon and Josef M Penninger}, doi = {10.1126/science.1173164}, issn = {1095-9203}, year = {2009}, date = {2009-01-01}, journal = {Science}, volume = {325}, number = {5938}, pages = {340--343}, abstract = {Innate immunity represents the first line of defense in animals. We report a genome-wide in vivo Drosophila RNA interference screen to uncover genes involved in susceptibility or resistance to intestinal infection with the bacterium Serratia marcescens. We first employed whole-organism gene suppression, followed by tissue-specific silencing in gut epithelium or hemocytes to identify several hundred genes involved in intestinal antibacterial immunity. Among the pathways identified, we showed that the JAK-STAT signaling pathway controls host defense in the gut by regulating stem cell proliferation and thus epithelial cell homeostasis. Therefore, we revealed multiple genes involved in antibacterial defense and the regulation of innate immunity.}, keywords = {*Genome, *RNA Interference, Animal, Animals, Cell Proliferation, Drosophila melanogaster/*genetics/immunology/*microbiology, Drosophila Proteins/genetics/metabolism, Epithelial Cells, Epithelial Cells/cytology/physiology, ferrandon, Genetically Modified, Genome, Hemocytes, Hemocytes/immunology/metabolism/microbiology, Homeostasis, Immunity, Innate, Innate/*genetics, Insect, Intestinal Mucosa, Intestinal Mucosa/cytology/immunology/metabolism/microbiology, Janus Kinases, Janus Kinases/genetics/metabolism, M3i, Models, RNA Interference, Serratia Infections, Serratia Infections/genetics/*immunology/microbiology, Serratia marcescens, Serratia marcescens/*immunology/physiology, Signal Transduction, STAT Transcription Factors, STAT Transcription Factors/genetics/metabolism, Stem Cells, Stem Cells/cytology/physiology}, pubstate = {published}, tppubtype = {article} } Innate immunity represents the first line of defense in animals. We report a genome-wide in vivo Drosophila RNA interference screen to uncover genes involved in susceptibility or resistance to intestinal infection with the bacterium Serratia marcescens. We first employed whole-organism gene suppression, followed by tissue-specific silencing in gut epithelium or hemocytes to identify several hundred genes involved in intestinal antibacterial immunity. Among the pathways identified, we showed that the JAK-STAT signaling pathway controls host defense in the gut by regulating stem cell proliferation and thus epithelial cell homeostasis. Therefore, we revealed multiple genes involved in antibacterial defense and the regulation of innate immunity. |
2008 |
Chamy, Laure El; Leclerc, Vincent; Caldelari, Isabelle; Reichhart, Jean-Marc Sensing of 'danger signals' and pathogen-associated molecular patterns defines binary signaling pathways 'upstream' of Toll Article de journal Nat. Immunol., 9 (10), p. 1165–1170, 2008, ISSN: 1529-2916. Résumé | Liens | BibTeX | Étiquettes: Animals, Fungi, Genetically Modified, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, In Situ Hybridization, M3i, Mycoses, Pattern Recognition, Peptide Hydrolases, Receptors, reichhart, Serine Endopeptidases, Signal Transduction, Toll-Like Receptors @article{el_chamy_sensing_2008, title = {Sensing of 'danger signals' and pathogen-associated molecular patterns defines binary signaling pathways 'upstream' of Toll}, author = {Laure El Chamy and Vincent Leclerc and Isabelle Caldelari and Jean-Marc Reichhart}, doi = {10.1038/ni.1643}, issn = {1529-2916}, year = {2008}, date = {2008-10-01}, journal = {Nat. Immunol.}, volume = {9}, number = {10}, pages = {1165--1170}, abstract = {In drosophila, molecular determinants from fungi and Gram-positive bacteria are detected by circulating pattern-recognition receptors. Published findings suggest that such pattern-recognition receptors activate as-yet-unidentified serine-protease cascades that culminate in the cleavage of Spätzle, the endogenous Toll receptor ligand, and trigger the immune response. We demonstrate here that the protease Grass defines a common activation cascade for the detection of fungi and Gram-positive bacteria mediated by pattern-recognition receptors. The serine protease Persephone, shown before to be specific for fungal detection in a cascade activated by secreted fungal proteases, was also required for the sensing of proteases elicited by bacteria in the hemolymph. Hence, Persephone defines a parallel proteolytic cascade activated by 'danger signals' such as abnormal proteolytic activities.}, keywords = {Animals, Fungi, Genetically Modified, Gram-Positive Bacteria, Gram-Positive Bacterial Infections, In Situ Hybridization, M3i, Mycoses, Pattern Recognition, Peptide Hydrolases, Receptors, reichhart, Serine Endopeptidases, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } In drosophila, molecular determinants from fungi and Gram-positive bacteria are detected by circulating pattern-recognition receptors. Published findings suggest that such pattern-recognition receptors activate as-yet-unidentified serine-protease cascades that culminate in the cleavage of Spätzle, the endogenous Toll receptor ligand, and trigger the immune response. We demonstrate here that the protease Grass defines a common activation cascade for the detection of fungi and Gram-positive bacteria mediated by pattern-recognition receptors. The serine protease Persephone, shown before to be specific for fungal detection in a cascade activated by secreted fungal proteases, was also required for the sensing of proteases elicited by bacteria in the hemolymph. Hence, Persephone defines a parallel proteolytic cascade activated by 'danger signals' such as abnormal proteolytic activities. |
Goto, Akira; Matsushita, Kazufumi; Gesellchen, Viola; Chamy, Laure El; Kuttenkeuler, David; Takeuchi, Osamu; Hoffmann, Jules A; Akira, Shizuo; Boutros, Michael; Reichhart, Jean-Marc Akirins are highly conserved nuclear proteins required for NF-kappaB-dependent gene expression in drosophila and mice Article de journal Nat. Immunol., 9 (1), p. 97–104, 2008, ISSN: 1529-2916. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Line, Embryo, Fibroblasts, hoffmann, Humans, Immunity, Innate, Interleukin-1beta, M3i, Mammalian, Mice, NF-kappa B, Nuclear Proteins, Proteins, reichhart, Signal Transduction, Toll-Like Receptors, transgenic, Tumor Necrosis Factor-alpha @article{goto_akirins_2008, title = {Akirins are highly conserved nuclear proteins required for NF-kappaB-dependent gene expression in drosophila and mice}, author = {Akira Goto and Kazufumi Matsushita and Viola Gesellchen and Laure El Chamy and David Kuttenkeuler and Osamu Takeuchi and Jules A Hoffmann and Shizuo Akira and Michael Boutros and Jean-Marc Reichhart}, doi = {10.1038/ni1543}, issn = {1529-2916}, year = {2008}, date = {2008-01-01}, journal = {Nat. Immunol.}, volume = {9}, number = {1}, pages = {97--104}, abstract = {During a genome-wide screen with RNA-mediated interference, we isolated CG8580 as a gene involved in the innate immune response of Drosophila melanogaster. CG8580, which we called Akirin, encoded a protein that acted in parallel with the NF-kappaB transcription factor downstream of the Imd pathway and was required for defense against Gram-negative bacteria. Akirin is highly conserved, and the human genome contains two homologs, one of which was able to rescue the loss-of-function phenotype in drosophila cells. Akirins were strictly localized to the nucleus. Knockout of both Akirin homologs in mice showed that one had an essential function downstream of the Toll-like receptor, tumor necrosis factor and interleukin (IL)-1beta signaling pathways leading to the production of IL-6. Thus, Akirin is a conserved nuclear factor required for innate immune responses.}, keywords = {Animals, Cell Line, Embryo, Fibroblasts, hoffmann, Humans, Immunity, Innate, Interleukin-1beta, M3i, Mammalian, Mice, NF-kappa B, Nuclear Proteins, Proteins, reichhart, Signal Transduction, Toll-Like Receptors, transgenic, Tumor Necrosis Factor-alpha}, pubstate = {published}, tppubtype = {article} } During a genome-wide screen with RNA-mediated interference, we isolated CG8580 as a gene involved in the innate immune response of Drosophila melanogaster. CG8580, which we called Akirin, encoded a protein that acted in parallel with the NF-kappaB transcription factor downstream of the Imd pathway and was required for defense against Gram-negative bacteria. Akirin is highly conserved, and the human genome contains two homologs, one of which was able to rescue the loss-of-function phenotype in drosophila cells. Akirins were strictly localized to the nucleus. Knockout of both Akirin homologs in mice showed that one had an essential function downstream of the Toll-like receptor, tumor necrosis factor and interleukin (IL)-1beta signaling pathways leading to the production of IL-6. Thus, Akirin is a conserved nuclear factor required for innate immune responses. |
2007 |
Weber, Alexander N R; Gangloff, Monique; Moncrieffe, Martin C; Hyvert, Yann; Imler, Jean-Luc; Gay, Nicholas J Role of the Spatzle Pro-domain in the generation of an active toll receptor ligand Article de journal The Journal of Biological Chemistry, 282 (18), p. 13522–13531, 2007, ISSN: 0021-9258. Résumé | Liens | BibTeX | Étiquettes: Animals, Cytokines, dimerization, imler, ligands, M3i, Post-Translational, Protein Binding, Protein Processing, Protein Structure, Signal Transduction, Tertiary, Toll-Like Receptors @article{weber_role_2007, title = {Role of the Spatzle Pro-domain in the generation of an active toll receptor ligand}, author = {Alexander N R Weber and Monique Gangloff and Martin C Moncrieffe and Yann Hyvert and Jean-Luc Imler and Nicholas J Gay}, doi = {10.1074/jbc.M700068200}, issn = {0021-9258}, year = {2007}, date = {2007-05-01}, journal = {The Journal of Biological Chemistry}, volume = {282}, number = {18}, pages = {13522--13531}, abstract = {The cytokine Spätzle is the ligand for Drosophila Toll, the prototype of an important family of membrane receptors that function in embryonic patterning and innate immunity. A dimeric precursor of Spätzle is processed by an endoprotease to produce a form (C-106) that cross-links Toll receptor ectodomains and establishes signaling. Here we show that before processing the pro-domain of Spätzle is required for correct biosynthesis and secretion. We mapped two loss-of-function mutations of Spätzle to a discrete site in the pro-domain and showed that the phenotype arises because of a defect in biosynthesis rather than signaling. We also report that the pro-domain and C-106 remain associated after cleavage and that this processed complex signals with the same characteristics as the C-terminal fragment. These results suggest that before activation the determinants on C-106 that bind specifically to Toll are sequestered by the pro-domain and that proteolytic processing causes conformational rearrangements that expose these determinants and enables binding to Toll. Furthermore, we show that the pro-domain is released when the Toll extracellular domain binds to the complex, a finding that has implications for the generation of a signaling-competent Toll dimer.}, keywords = {Animals, Cytokines, dimerization, imler, ligands, M3i, Post-Translational, Protein Binding, Protein Processing, Protein Structure, Signal Transduction, Tertiary, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The cytokine Spätzle is the ligand for Drosophila Toll, the prototype of an important family of membrane receptors that function in embryonic patterning and innate immunity. A dimeric precursor of Spätzle is processed by an endoprotease to produce a form (C-106) that cross-links Toll receptor ectodomains and establishes signaling. Here we show that before processing the pro-domain of Spätzle is required for correct biosynthesis and secretion. We mapped two loss-of-function mutations of Spätzle to a discrete site in the pro-domain and showed that the phenotype arises because of a defect in biosynthesis rather than signaling. We also report that the pro-domain and C-106 remain associated after cleavage and that this processed complex signals with the same characteristics as the C-terminal fragment. These results suggest that before activation the determinants on C-106 that bind specifically to Toll are sequestered by the pro-domain and that proteolytic processing causes conformational rearrangements that expose these determinants and enables binding to Toll. Furthermore, we show that the pro-domain is released when the Toll extracellular domain binds to the complex, a finding that has implications for the generation of a signaling-competent Toll dimer. |
2006 |
Gottar, Marie; Gobert, Vanessa; Matskevich, Alexey A; Reichhart, Jean-Marc; Wang, Chengshu; Butt, Tariq M; Belvin, Marcia; Hoffmann, Jules A; Ferrandon, Dominique Dual detection of fungal infections in Drosophila via recognition of glucans and sensing of virulence factors Article de journal Cell, 127 (7), p. 1425–1437, 2006, ISSN: 0092-8674. Résumé | Liens | BibTeX | Étiquettes: Animals, Antibody Formation, Beauveria, Candida albicans, Carrier Proteins, Cellular, ferrandon, Glucans, hoffmann, Immunity, Immunological, M3i, Metarhizium, Models, Polysaccharides, reichhart, Serine Endopeptidases, Signal Transduction, Virulence Factors @article{gottar_dual_2006, title = {Dual detection of fungal infections in Drosophila via recognition of glucans and sensing of virulence factors}, author = {Marie Gottar and Vanessa Gobert and Alexey A Matskevich and Jean-Marc Reichhart and Chengshu Wang and Tariq M Butt and Marcia Belvin and Jules A Hoffmann and Dominique Ferrandon}, doi = {10.1016/j.cell.2006.10.046}, issn = {0092-8674}, year = {2006}, date = {2006-12-01}, journal = {Cell}, volume = {127}, number = {7}, pages = {1425--1437}, abstract = {The Drosophila immune system discriminates between various types of infections and activates appropriate signal transduction pathways to combat the invading microorganisms. The Toll pathway is required for the host response against fungal and most Gram-positive bacterial infections. The sensing of Gram-positive bacteria is mediated by the pattern recognition receptors PGRP-SA and GNBP1 that cooperate to detect the presence of infections in the host. Here, we report that GNBP3 is a pattern recognition receptor that is required for the detection of fungal cell wall components. Strikingly, we find that there is a second, parallel pathway acting jointly with GNBP3. The Drosophila Persephone protease activates the Toll pathway when proteolytically matured by the secreted fungal virulence factor PR1. Thus, the detection of fungal infections in Drosophila relies both on the recognition of invariant microbial patterns and on monitoring the effects of virulence factors on the host.}, keywords = {Animals, Antibody Formation, Beauveria, Candida albicans, Carrier Proteins, Cellular, ferrandon, Glucans, hoffmann, Immunity, Immunological, M3i, Metarhizium, Models, Polysaccharides, reichhart, Serine Endopeptidases, Signal Transduction, Virulence Factors}, pubstate = {published}, tppubtype = {article} } The Drosophila immune system discriminates between various types of infections and activates appropriate signal transduction pathways to combat the invading microorganisms. The Toll pathway is required for the host response against fungal and most Gram-positive bacterial infections. The sensing of Gram-positive bacteria is mediated by the pattern recognition receptors PGRP-SA and GNBP1 that cooperate to detect the presence of infections in the host. Here, we report that GNBP3 is a pattern recognition receptor that is required for the detection of fungal cell wall components. Strikingly, we find that there is a second, parallel pathway acting jointly with GNBP3. The Drosophila Persephone protease activates the Toll pathway when proteolytically matured by the secreted fungal virulence factor PR1. Thus, the detection of fungal infections in Drosophila relies both on the recognition of invariant microbial patterns and on monitoring the effects of virulence factors on the host. |
Evans, J D; Aronstein, K; Chen, Y P; Hetru, Charles; Imler, Jean-Luc; Jiang, H; Kanost, M; Thompson, G J; Zou, Z; Hultmark, D Immune pathways and defence mechanisms in honey bees Apis mellifera Article de journal Insect Molecular Biology, 15 (5), p. 645–656, 2006, ISSN: 0962-1075. Résumé | Liens | BibTeX | Étiquettes: Animals, Bees, Carrier Proteins, Genome, imler, Immunity, Insect, Janus Kinases, M3i, Multigene Family, Serine Endopeptidases, Signal Transduction, STAT Transcription Factors, Toll-Like Receptors @article{evans_immune_2006, title = {Immune pathways and defence mechanisms in honey bees Apis mellifera}, author = {J D Evans and K Aronstein and Y P Chen and Charles Hetru and Jean-Luc Imler and H Jiang and M Kanost and G J Thompson and Z Zou and D Hultmark}, doi = {10.1111/j.1365-2583.2006.00682.x}, issn = {0962-1075}, year = {2006}, date = {2006-10-01}, journal = {Insect Molecular Biology}, volume = {15}, number = {5}, pages = {645--656}, abstract = {Social insects are able to mount both group-level and individual defences against pathogens. Here we focus on individual defences, by presenting a genome-wide analysis of immunity in a social insect, the honey bee Apis mellifera. We present honey bee models for each of four signalling pathways associated with immunity, identifying plausible orthologues for nearly all predicted pathway members. When compared to the sequenced Drosophila and Anopheles genomes, honey bees possess roughly one-third as many genes in 17 gene families implicated in insect immunity. We suggest that an implied reduction in immune flexibility in bees reflects either the strength of social barriers to disease, or a tendency for bees to be attacked by a limited set of highly coevolved pathogens.}, keywords = {Animals, Bees, Carrier Proteins, Genome, imler, Immunity, Insect, Janus Kinases, M3i, Multigene Family, Serine Endopeptidases, Signal Transduction, STAT Transcription Factors, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Social insects are able to mount both group-level and individual defences against pathogens. Here we focus on individual defences, by presenting a genome-wide analysis of immunity in a social insect, the honey bee Apis mellifera. We present honey bee models for each of four signalling pathways associated with immunity, identifying plausible orthologues for nearly all predicted pathway members. When compared to the sequenced Drosophila and Anopheles genomes, honey bees possess roughly one-third as many genes in 17 gene families implicated in insect immunity. We suggest that an implied reduction in immune flexibility in bees reflects either the strength of social barriers to disease, or a tendency for bees to be attacked by a limited set of highly coevolved pathogens. |
Bischoff, Vincent; Vignal, Cécile; Duvic, Bernard; Boneca, Ivo G; Hoffmann, Jules A; Royet, Julien Downregulation of the Drosophila immune response by peptidoglycan-recognition proteins SC1 and SC2 Article de journal PLoS Pathog., 2 (2), p. e14, 2006, ISSN: 1553-7374. Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, bacteria, Carrier Proteins, Down-Regulation, hoffmann, Larva, M3i, RNA Interference, Signal Transduction @article{bischoff_downregulation_2006, title = {Downregulation of the Drosophila immune response by peptidoglycan-recognition proteins SC1 and SC2}, author = {Vincent Bischoff and Cécile Vignal and Bernard Duvic and Ivo G Boneca and Jules A Hoffmann and Julien Royet}, doi = {10.1371/journal.ppat.0020014}, issn = {1553-7374}, year = {2006}, date = {2006-02-01}, journal = {PLoS Pathog.}, volume = {2}, number = {2}, pages = {e14}, abstract = {Peptidoglycan-recognition proteins (PGRPs) are evolutionarily conserved molecules that are structurally related to bacterial amidases. Several Drosophila PGRPs have lost this enzymatic activity and serve as microbe sensors through peptidoglycan recognition. Other PGRP family members, such as Drosophila PGRP-SC1 or mammalian PGRP-L, have conserved the amidase function and are able to cleave peptidoglycan in vitro. However, the contribution of these amidase PGRPs to host defense in vivo has remained elusive so far. Using an RNA-interference approach, we addressed the function of two PGRPs with amidase activity in the Drosophila immune response. We observed that PGRP-SC1/2-depleted flies present a specific over-activation of the IMD (immune deficiency) signaling pathway after bacterial challenge. Our data suggest that these proteins act in the larval gut to prevent activation of this pathway following bacterial ingestion. We further show that a strict control of IMD-pathway activation is essential to prevent bacteria-induced developmental defects and larval death.}, keywords = {Animals, Antimicrobial Cationic Peptides, bacteria, Carrier Proteins, Down-Regulation, hoffmann, Larva, M3i, RNA Interference, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Peptidoglycan-recognition proteins (PGRPs) are evolutionarily conserved molecules that are structurally related to bacterial amidases. Several Drosophila PGRPs have lost this enzymatic activity and serve as microbe sensors through peptidoglycan recognition. Other PGRP family members, such as Drosophila PGRP-SC1 or mammalian PGRP-L, have conserved the amidase function and are able to cleave peptidoglycan in vitro. However, the contribution of these amidase PGRPs to host defense in vivo has remained elusive so far. Using an RNA-interference approach, we addressed the function of two PGRPs with amidase activity in the Drosophila immune response. We observed that PGRP-SC1/2-depleted flies present a specific over-activation of the IMD (immune deficiency) signaling pathway after bacterial challenge. Our data suggest that these proteins act in the larval gut to prevent activation of this pathway following bacterial ingestion. We further show that a strict control of IMD-pathway activation is essential to prevent bacteria-induced developmental defects and larval death. |
Pelte, Nadège; Robertson, Andrew S; Zou, Zhen; Belorgey, Didier; Dafforn, Timothy R; Jiang, Haobo; Lomas, David; Reichhart, Jean-Marc; Gubb, David Immune challenge induces N-terminal cleavage of the Drosophila serpin Necrotic Article de journal Insect Biochem. Mol. Biol., 36 (1), p. 37–46, 2006, ISSN: 0965-1748. Résumé | Liens | BibTeX | Étiquettes: Animals, Gene Expression Regulation, M3i, Protein Conformation, reichhart, Serpins, Signal Transduction @article{pelte_immune_2006, title = {Immune challenge induces N-terminal cleavage of the Drosophila serpin Necrotic}, author = {Nadège Pelte and Andrew S Robertson and Zhen Zou and Didier Belorgey and Timothy R Dafforn and Haobo Jiang and David Lomas and Jean-Marc Reichhart and David Gubb}, doi = {10.1016/j.ibmb.2005.10.004}, issn = {0965-1748}, year = {2006}, date = {2006-01-01}, journal = {Insect Biochem. Mol. Biol.}, volume = {36}, number = {1}, pages = {37--46}, abstract = {The Drosophila Necrotic protein is a serine proteinase inhibitor, which regulates the Toll-mediated innate immune response. Necrotic specifically inhibits an extracellular serine proteinase cascade leading to activation of the Toll ligand, Spätzle. Necrotic carries a polyglutamine extension amino-terminal to the core serpin structure. We show here that cleavage of this N-terminal extension occurs following immune challenge. This modification is blocked in PGRP-SA(semmelweiss) mutants after Gram-positive bacterial challenge and in persephone mutants after fungal or Gram-positive bacterial challenge, indicating that activation of either of the Toll pathway upstream branches induces N-terminal cleavage of the serpin. The absolute requirement of persephone gene product for this cleavage indicates that Gram-positive bacteria activate a redundant set of proteinases upstream of Toll. Both full-length Necrotic and the core serpin are active inhibitors of a range of serine proteinases: the highest affinity being for cathepsin G and elastases. We found a 13-fold increase in the specificity of the core serpin over that of full-length Necrotic for one of the tested proteinases (porcine pancreatic elastase). This finding indicates that cleavage of the Necrotic amino-terminal extension might modulate Toll activation following the initial immune response.}, keywords = {Animals, Gene Expression Regulation, M3i, Protein Conformation, reichhart, Serpins, Signal Transduction}, pubstate = {published}, tppubtype = {article} } The Drosophila Necrotic protein is a serine proteinase inhibitor, which regulates the Toll-mediated innate immune response. Necrotic specifically inhibits an extracellular serine proteinase cascade leading to activation of the Toll ligand, Spätzle. Necrotic carries a polyglutamine extension amino-terminal to the core serpin structure. We show here that cleavage of this N-terminal extension occurs following immune challenge. This modification is blocked in PGRP-SA(semmelweiss) mutants after Gram-positive bacterial challenge and in persephone mutants after fungal or Gram-positive bacterial challenge, indicating that activation of either of the Toll pathway upstream branches induces N-terminal cleavage of the serpin. The absolute requirement of persephone gene product for this cleavage indicates that Gram-positive bacteria activate a redundant set of proteinases upstream of Toll. Both full-length Necrotic and the core serpin are active inhibitors of a range of serine proteinases: the highest affinity being for cathepsin G and elastases. We found a 13-fold increase in the specificity of the core serpin over that of full-length Necrotic for one of the tested proteinases (porcine pancreatic elastase). This finding indicates that cleavage of the Necrotic amino-terminal extension might modulate Toll activation following the initial immune response. |
Galiana-Arnoux, Delphine; Imler, Jean-Luc Toll-like receptors and innate antiviral immunity Article de journal Tissue Antigens, 67 (4), p. 267–276, 2006, ISSN: 0001-2815. Résumé | Liens | BibTeX | Étiquettes: Animals, Humans, imler, Immunity, Innate, M3i, Signal Transduction, Toll-Like Receptors, Virus Diseases @article{galiana-arnoux_toll-like_2006, title = {Toll-like receptors and innate antiviral immunity}, author = {Delphine Galiana-Arnoux and Jean-Luc Imler}, doi = {10.1111/j.1399-0039.2006.00583.x}, issn = {0001-2815}, year = {2006}, date = {2006-01-01}, journal = {Tissue Antigens}, volume = {67}, number = {4}, pages = {267--276}, abstract = {Viral infections are first detected by a set of innate immunity receptors that detect primary infections by pathogens, and trigger a transcriptional response. Among the induced target genes, type I interferons (IFNs) are central to the antiviral response of the host. The receptors and signaling pathways that mediate the strong induction of the synthesis of these cytokines have long remained elusive. In the past few years, Toll-like receptors (TLRs) emerged as important sensors of infections. Several TLRs participate in the recognition of virus infection, interacting in particular with viral nucleic acids. Upon activation, TLRs interact with different cytosolic adapter molecules and activate transcription factors of the nuclear factor-kappaB and IFN regulatory factor families that concur to mediate induction of IFN-alpha/beta and other inflammatory cytokines. In addition to the transmembrane TLRs, cytosolic helicases also detect viral nucleic acids, and trigger type I IFN synthesis.}, keywords = {Animals, Humans, imler, Immunity, Innate, M3i, Signal Transduction, Toll-Like Receptors, Virus Diseases}, pubstate = {published}, tppubtype = {article} } Viral infections are first detected by a set of innate immunity receptors that detect primary infections by pathogens, and trigger a transcriptional response. Among the induced target genes, type I interferons (IFNs) are central to the antiviral response of the host. The receptors and signaling pathways that mediate the strong induction of the synthesis of these cytokines have long remained elusive. In the past few years, Toll-like receptors (TLRs) emerged as important sensors of infections. Several TLRs participate in the recognition of virus infection, interacting in particular with viral nucleic acids. Upon activation, TLRs interact with different cytosolic adapter molecules and activate transcription factors of the nuclear factor-kappaB and IFN regulatory factor families that concur to mediate induction of IFN-alpha/beta and other inflammatory cytokines. In addition to the transmembrane TLRs, cytosolic helicases also detect viral nucleic acids, and trigger type I IFN synthesis. |
2005 |
Royet, Julien; Reichhart, Jean-Marc; Hoffmann, Jules A Sensing and signaling during infection in Drosophila Article de journal Curr. Opin. Immunol., 17 (1), p. 11–17, 2005, ISSN: 0952-7915. Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, Bacterial Infections, Gene Expression Regulation, Genome, hoffmann, Immunity, Innate, M3i, reichhart, Signal Transduction @article{royet_sensing_2005, title = {Sensing and signaling during infection in Drosophila}, author = {Julien Royet and Jean-Marc Reichhart and Jules A Hoffmann}, doi = {10.1016/j.coi.2004.12.002}, issn = {0952-7915}, year = {2005}, date = {2005-02-01}, journal = {Curr. Opin. Immunol.}, volume = {17}, number = {1}, pages = {11--17}, abstract = {Most of the progress in dissecting the Drosophila antimicrobial response over the past decade has centered around intracellular signaling pathways in immune response tissues and expression of genes encoding antimicrobial peptide genes. The past few years, however, have witnessed significant advances in our understanding of the recognition of microbial invaders and subsequent activation of signaling cascades. In particular, the roles of peptidoglycan recognition proteins, which have known homologues in mammals, have been recognized and examined at the structural and functional levels.}, keywords = {Animals, Antimicrobial Cationic Peptides, Bacterial Infections, Gene Expression Regulation, Genome, hoffmann, Immunity, Innate, M3i, reichhart, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Most of the progress in dissecting the Drosophila antimicrobial response over the past decade has centered around intracellular signaling pathways in immune response tissues and expression of genes encoding antimicrobial peptide genes. The past few years, however, have witnessed significant advances in our understanding of the recognition of microbial invaders and subsequent activation of signaling cascades. In particular, the roles of peptidoglycan recognition proteins, which have known homologues in mammals, have been recognized and examined at the structural and functional levels. |
Dostert, Catherine; Jouanguy, Emmanuelle; Irving, Phil; Troxler, Laurent; Galiana-Arnoux, Delphine; Hetru, Charles; Hoffmann, Jules A; Imler, Jean-Luc The Jak-STAT signaling pathway is required but not sufficient for the antiviral response of drosophila Article de journal Nature Immunology, 6 (9), p. 946–953, 2005, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, DNA-Binding Proteins, Genetic, Genetically Modified, hoffmann, imler, Insect Viruses, Janus Kinase 1, M3i, Male, Oligonucleotide Array Sequence Analysis, Promoter Regions, Protein-Tyrosine Kinases, Signal Transduction, STAT1 Transcription Factor, Trans-Activators @article{dostert_jak-stat_2005, title = {The Jak-STAT signaling pathway is required but not sufficient for the antiviral response of drosophila}, author = {Catherine Dostert and Emmanuelle Jouanguy and Phil Irving and Laurent Troxler and Delphine Galiana-Arnoux and Charles Hetru and Jules A Hoffmann and Jean-Luc Imler}, doi = {10.1038/ni1237}, issn = {1529-2908}, year = {2005}, date = {2005-01-01}, journal = {Nature Immunology}, volume = {6}, number = {9}, pages = {946--953}, abstract = {The response of drosophila to bacterial and fungal infections involves two signaling pathways, Toll and Imd, which both activate members of the transcription factor NF-kappaB family. Here we have studied the global transcriptional response of flies to infection with drosophila C virus. Viral infection induced a set of genes distinct from those regulated by the Toll or Imd pathways and triggered a signal transducer and activator of transcription (STAT) DNA-binding activity. Genetic experiments showed that the Jak kinase Hopscotch was involved in the control of the viral load in infected flies and was required but not sufficient for the induction of some virus-regulated genes. Our results indicate that in addition to Toll and Imd, a third, evolutionary conserved innate immunity pathway functions in drosophila and counters viral infection.}, keywords = {Animals, bioinformatic, DNA-Binding Proteins, Genetic, Genetically Modified, hoffmann, imler, Insect Viruses, Janus Kinase 1, M3i, Male, Oligonucleotide Array Sequence Analysis, Promoter Regions, Protein-Tyrosine Kinases, Signal Transduction, STAT1 Transcription Factor, Trans-Activators}, pubstate = {published}, tppubtype = {article} } The response of drosophila to bacterial and fungal infections involves two signaling pathways, Toll and Imd, which both activate members of the transcription factor NF-kappaB family. Here we have studied the global transcriptional response of flies to infection with drosophila C virus. Viral infection induced a set of genes distinct from those regulated by the Toll or Imd pathways and triggered a signal transducer and activator of transcription (STAT) DNA-binding activity. Genetic experiments showed that the Jak kinase Hopscotch was involved in the control of the viral load in infected flies and was required but not sufficient for the induction of some virus-regulated genes. Our results indicate that in addition to Toll and Imd, a third, evolutionary conserved innate immunity pathway functions in drosophila and counters viral infection. |
Martinelli, Cosimo; Reichhart, Jean-Marc Evolution and integration of innate immune systems from fruit flies to man: lessons and questions Article de journal J. Endotoxin Res., 11 (4), p. 243–248, 2005, ISSN: 0968-0519. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological Evolution, Cell Surface, Forecasting, Humans, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors @article{martinelli_evolution_2005, title = {Evolution and integration of innate immune systems from fruit flies to man: lessons and questions}, author = {Cosimo Martinelli and Jean-Marc Reichhart}, doi = {10.1179/096805105X37411}, issn = {0968-0519}, year = {2005}, date = {2005-01-01}, journal = {J. Endotoxin Res.}, volume = {11}, number = {4}, pages = {243--248}, abstract = {Despite broad differences in morphology, ecology and behavior, the fruit fly Drosophila melanogaster and humans show a remarkably high degree of conservation for many molecular, cellular, and developmental aspects of their biology. During the last decade, similarities have also been discovered in some of the mechanisms regulating their innate immune system. These parallels regard mainly the Toll-like receptor family and the intracellular signaling pathways involved in the control of the immune response. However, if the overall similarities are important, the detailed pathogen recognition mechanisms differ significantly between fly and humans, highlighting a complicated evolutionary history of the metazoan innate defenses. In this review, we will discuss the main similarities and differences between the two types of organisms. We hope that this current knowledge will be used as a starting point for a more comprehensive view of innate immunity within the broad variety of metazoan phyla.}, keywords = {Animals, Biological Evolution, Cell Surface, Forecasting, Humans, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Despite broad differences in morphology, ecology and behavior, the fruit fly Drosophila melanogaster and humans show a remarkably high degree of conservation for many molecular, cellular, and developmental aspects of their biology. During the last decade, similarities have also been discovered in some of the mechanisms regulating their innate immune system. These parallels regard mainly the Toll-like receptor family and the intracellular signaling pathways involved in the control of the immune response. However, if the overall similarities are important, the detailed pathogen recognition mechanisms differ significantly between fly and humans, highlighting a complicated evolutionary history of the metazoan innate defenses. In this review, we will discuss the main similarities and differences between the two types of organisms. We hope that this current knowledge will be used as a starting point for a more comprehensive view of innate immunity within the broad variety of metazoan phyla. |
Weber, Alexander N R; Moncrieffe, Martin C; Gangloff, Monique; Imler, Jean-Luc; Gay, Nicholas J Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway Article de journal The Journal of Biological Chemistry, 280 (24), p. 22793–22799, 2005, ISSN: 0021-9258. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation @article{weber_ligand-receptor_2005, title = {Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway}, author = {Alexander N R Weber and Martin C Moncrieffe and Monique Gangloff and Jean-Luc Imler and Nicholas J Gay}, doi = {10.1074/jbc.M502074200}, issn = {0021-9258}, year = {2005}, date = {2005-01-01}, journal = {The Journal of Biological Chemistry}, volume = {280}, number = {24}, pages = {22793--22799}, abstract = {In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions.}, keywords = {Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation}, pubstate = {published}, tppubtype = {article} } In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions. |
Imler, Jean-Luc; Bulet, Philippe Antimicrobial peptides in Drosophila: structures, activities and gene regulation Article de journal Chemical Immunology and Allergy, 86 , p. 1–21, 2005, ISSN: 1660-2242. Résumé | Liens | BibTeX | Étiquettes: Animals, Antimicrobial Cationic Peptides, Defensins, Gene Expression Regulation, Genes, Glycopeptides, imler, Immunity, Innate, Insect, Insect Proteins, M3i, Molecular Structure, Signal Transduction @article{imler_antimicrobial_2005, title = {Antimicrobial peptides in Drosophila: structures, activities and gene regulation}, author = {Jean-Luc Imler and Philippe Bulet}, doi = {10.1159/000086648}, issn = {1660-2242}, year = {2005}, date = {2005-01-01}, journal = {Chemical Immunology and Allergy}, volume = {86}, pages = {1--21}, abstract = {The production of antimicrobial peptides (AMPs) is an important aspect of host-defence in multicellular organisms. Biochemical analysis of the hemolymph of the fruit-fly Drosophila melanogaster and other Diptera has led to the discovery of eight classes of AMPs. These peptides can be grouped into three families based on their main biological targets, gram-positive bacteria (defensin), gram-negative bacteria (cecropins, drosocin, attacins, diptericin, MPAC), or fungi (drosomycin, metchnikowin). Drosophila AMPs are synthesized by the fat body in response to infection, and secreted into the blood. Most of them can also be induced in surface epithelia in a tissue-specific manner. Finally, some of them are constitutively expressed in defined tissues, such as the salivary glands or the reproductive tract. We review here the structures and activities of these AMPs, as well as the signalling cascades, which lead to their induction upon detection of infectious non-self.}, keywords = {Animals, Antimicrobial Cationic Peptides, Defensins, Gene Expression Regulation, Genes, Glycopeptides, imler, Immunity, Innate, Insect, Insect Proteins, M3i, Molecular Structure, Signal Transduction}, pubstate = {published}, tppubtype = {article} } The production of antimicrobial peptides (AMPs) is an important aspect of host-defence in multicellular organisms. Biochemical analysis of the hemolymph of the fruit-fly Drosophila melanogaster and other Diptera has led to the discovery of eight classes of AMPs. These peptides can be grouped into three families based on their main biological targets, gram-positive bacteria (defensin), gram-negative bacteria (cecropins, drosocin, attacins, diptericin, MPAC), or fungi (drosomycin, metchnikowin). Drosophila AMPs are synthesized by the fat body in response to infection, and secreted into the blood. Most of them can also be induced in surface epithelia in a tissue-specific manner. Finally, some of them are constitutively expressed in defined tissues, such as the salivary glands or the reproductive tract. We review here the structures and activities of these AMPs, as well as the signalling cascades, which lead to their induction upon detection of infectious non-self. |
2004 |
Irving, Phil; Troxler, Laurent; Hetru, Charles Is innate enough? The innate immune response in Drosophila Article de journal C. R. Biol., 327 (6), p. 557–570, 2004, ISSN: 1631-0691. Résumé | BibTeX | Étiquettes: Animals, bioinformatic, Immunity, Innate, M3i, Signal Transduction @article{irving_is_2004, title = {Is innate enough? The innate immune response in Drosophila}, author = {Phil Irving and Laurent Troxler and Charles Hetru}, issn = {1631-0691}, year = {2004}, date = {2004-06-01}, journal = {C. R. Biol.}, volume = {327}, number = {6}, pages = {557--570}, abstract = {In recent years, the innate immune system has emerged from the shadow of adaptive immune responses as a major area of research in its own right. One of the most significant model systems that has been used to investigate this phenomenon has been the fruit fly, Drosophila melanogaster. Exploration of the differential immune response presented by Drosophila led to the discovery of important signalling events and transduction pathways, which were thereafter shown to be specific for the type of infecting pathogen. These factors and pathways were subsequently found to have homologues in many other organisms, including those with adaptive immune responses. In light of the present status of studies in innate immunity, this review describes the current state of understanding of the Drosophila immune response.}, keywords = {Animals, bioinformatic, Immunity, Innate, M3i, Signal Transduction}, pubstate = {published}, tppubtype = {article} } In recent years, the innate immune system has emerged from the shadow of adaptive immune responses as a major area of research in its own right. One of the most significant model systems that has been used to investigate this phenomenon has been the fruit fly, Drosophila melanogaster. Exploration of the differential immune response presented by Drosophila led to the discovery of important signalling events and transduction pathways, which were thereafter shown to be specific for the type of infecting pathogen. These factors and pathways were subsequently found to have homologues in many other organisms, including those with adaptive immune responses. In light of the present status of studies in innate immunity, this review describes the current state of understanding of the Drosophila immune response. |
Leclerc, Vincent; Reichhart, Jean-Marc The immune response of Drosophila melanogaster Article de journal Immunol. Rev., 198 , p. 59–71, 2004, ISSN: 0105-2896. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, Immunity, Immunological, Innate, M3i, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors @article{leclerc_immune_2004, title = {The immune response of Drosophila melanogaster}, author = {Vincent Leclerc and Jean-Marc Reichhart}, issn = {0105-2896}, year = {2004}, date = {2004-04-01}, journal = {Immunol. Rev.}, volume = {198}, pages = {59--71}, abstract = {The response of the fruit fly Drosophila melanogaster to various microorganism infections relies on a multilayered defense. The epithelia constitute a first and efficient barrier. Innate immunity is activated when microorganisms succeed in entering the body cavity of the fly. Invading microorganisms are killed by the combined action of cellular and humoral processes. They are phagocytosed by specialized blood cells, surrounded by toxic melanin, or lysed by antibacterial peptides secreted into the hemolymph by fat body cells. During the last few years, research has focused on the mechanisms of microbial recognition by various pattern recognition receptors and of the subsequent induction of antimicrobial peptide expression. The cellular arm of the Drosophila innate immune system, which was somehow neglected, now constitutes the new frontier.}, keywords = {Animals, Cell Surface, Immunity, Immunological, Innate, M3i, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The response of the fruit fly Drosophila melanogaster to various microorganism infections relies on a multilayered defense. The epithelia constitute a first and efficient barrier. Innate immunity is activated when microorganisms succeed in entering the body cavity of the fly. Invading microorganisms are killed by the combined action of cellular and humoral processes. They are phagocytosed by specialized blood cells, surrounded by toxic melanin, or lysed by antibacterial peptides secreted into the hemolymph by fat body cells. During the last few years, research has focused on the mechanisms of microbial recognition by various pattern recognition receptors and of the subsequent induction of antimicrobial peptide expression. The cellular arm of the Drosophila innate immune system, which was somehow neglected, now constitutes the new frontier. |
Imler, Jean-Luc; Zheng, Liangbiao Biology of Toll receptors: lessons from insects and mammals Article de journal Journal of Leukocyte Biology, 75 (1), p. 18–26, 2004, ISSN: 0741-5400. Résumé | Liens | BibTeX | Étiquettes: Animals, Anopheles, Cell Surface, Humans, imler, M3i, Membrane Glycoproteins, Mice, Phylogeny, Plant Physiological Phenomena, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors @article{imler_biology_2004, title = {Biology of Toll receptors: lessons from insects and mammals}, author = {Jean-Luc Imler and Liangbiao Zheng}, doi = {10.1189/jlb.0403160}, issn = {0741-5400}, year = {2004}, date = {2004-01-01}, journal = {Journal of Leukocyte Biology}, volume = {75}, number = {1}, pages = {18--26}, abstract = {Toll receptors are type I transmembrane proteins that play important roles in development and immunity in animals. Comparison of the genomes of mouse and human on one side and of the fruitfly Drosophila and the mosquito Anopheles (two dipteran insects) on the other, revealed that the four species possess a similar number of Toll receptors (approximately 10). However, phylogenetic analyses indicate that the families of Toll receptors expanded independently in insects and mammals. We review recent results on these receptors, which point to differences in the activation and signaling between Tolls in insects and Toll-like receptors (TLRs) in mammals. Whereas mammalian TLRs appear to be solely dedicated to host-defense, insect Tolls may be predominantly linked to other functions, probably developmental.}, keywords = {Animals, Anopheles, Cell Surface, Humans, imler, M3i, Membrane Glycoproteins, Mice, Phylogeny, Plant Physiological Phenomena, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Toll receptors are type I transmembrane proteins that play important roles in development and immunity in animals. Comparison of the genomes of mouse and human on one side and of the fruitfly Drosophila and the mosquito Anopheles (two dipteran insects) on the other, revealed that the four species possess a similar number of Toll receptors (approximately 10). However, phylogenetic analyses indicate that the families of Toll receptors expanded independently in insects and mammals. We review recent results on these receptors, which point to differences in the activation and signaling between Tolls in insects and Toll-like receptors (TLRs) in mammals. Whereas mammalian TLRs appear to be solely dedicated to host-defense, insect Tolls may be predominantly linked to other functions, probably developmental. |
2003 |
Ligoxygakis, Petros; Roth, Siegfried; Reichhart, Jean-Marc A serpin regulates dorsal-ventral axis formation in the Drosophila embryo Article de journal Curr. Biol., 13 (23), p. 2097–2102, 2003, ISSN: 0960-9822. Résumé | BibTeX | Étiquettes: Animals, Body Patterning, Cell Surface, Crosses, Female, Genetic, Immunohistochemistry, M3i, Microinjections, Receptors, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors @article{ligoxygakis_serpin_2003, title = {A serpin regulates dorsal-ventral axis formation in the Drosophila embryo}, author = {Petros Ligoxygakis and Siegfried Roth and Jean-Marc Reichhart}, issn = {0960-9822}, year = {2003}, date = {2003-12-01}, journal = {Curr. Biol.}, volume = {13}, number = {23}, pages = {2097--2102}, abstract = {Extracellular serine protease cascades have evolved in vertebrates and invertebrates to mediate rapid, local reactions to physiological or pathological cues. The serine protease cascade that triggers the Toll signaling pathway in Drosophila embryogenesis shares several organizational characteristics with those involved in mammalian complement and blood clotting. One of the hallmarks of such cascades is their regulation by serine protease inhibitors (serpins). Serpins act as suicide substrates and are cleaved by their target protease, forming an essentially irreversible 1:1 complex. The biological importance of serpins is highlighted by serpin dysfunction diseases, such as thrombosis caused by a deficiency in antithrombin. Here, we describe how a serpin controls the serine protease cascade, leading to Toll pathway activation. Female flies deficient in Serpin-27A produce embryos that lack dorsal-ventral polarity and show uniform high levels of Toll signaling. Since this serpin has been recently shown to restrain an immune reaction in the blood of Drosophila, it demonstrates that proteolysis can be regulated by the same serpin in different biological contexts.}, keywords = {Animals, Body Patterning, Cell Surface, Crosses, Female, Genetic, Immunohistochemistry, M3i, Microinjections, Receptors, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Extracellular serine protease cascades have evolved in vertebrates and invertebrates to mediate rapid, local reactions to physiological or pathological cues. The serine protease cascade that triggers the Toll signaling pathway in Drosophila embryogenesis shares several organizational characteristics with those involved in mammalian complement and blood clotting. One of the hallmarks of such cascades is their regulation by serine protease inhibitors (serpins). Serpins act as suicide substrates and are cleaved by their target protease, forming an essentially irreversible 1:1 complex. The biological importance of serpins is highlighted by serpin dysfunction diseases, such as thrombosis caused by a deficiency in antithrombin. Here, we describe how a serpin controls the serine protease cascade, leading to Toll pathway activation. Female flies deficient in Serpin-27A produce embryos that lack dorsal-ventral polarity and show uniform high levels of Toll signaling. Since this serpin has been recently shown to restrain an immune reaction in the blood of Drosophila, it demonstrates that proteolysis can be regulated by the same serpin in different biological contexts. |
Royet, Julien; Reichhart, Jean-Marc Detection of peptidoglycans by NOD proteins Article de journal Trends Cell Biol., 13 (12), p. 610–614, 2003, ISSN: 0962-8924. Résumé | BibTeX | Étiquettes: Adaptor Proteins, Apoptosis, Carrier Proteins, Gram-Positive Bacteria, Humans, Immunity, Immunologic, Innate, M3i, Nod1 Signaling Adaptor Protein, Oligopeptides, peptidoglycan, Receptors, reichhart, Signal Transducing, Signal Transduction @article{royet_detection_2003, title = {Detection of peptidoglycans by NOD proteins}, author = {Julien Royet and Jean-Marc Reichhart}, issn = {0962-8924}, year = {2003}, date = {2003-12-01}, journal = {Trends Cell Biol.}, volume = {13}, number = {12}, pages = {610--614}, abstract = {Mechanisms of innate immune defense are based on the recognition of invariant microbial molecular patterns by specific receptors, followed by the activation of signaling pathways and the expression of effector molecules that will defeat the invading microorganism. Two recent reports add to the growing list of these pattern-recognition receptors by showing that the intracellular nucleotide-binding oligomerization domain 1 (NOD1) protein recognizes a diaminopimelate-containing muropeptide, a cell-wall component of Gram-negative bacteria.}, keywords = {Adaptor Proteins, Apoptosis, Carrier Proteins, Gram-Positive Bacteria, Humans, Immunity, Immunologic, Innate, M3i, Nod1 Signaling Adaptor Protein, Oligopeptides, peptidoglycan, Receptors, reichhart, Signal Transducing, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Mechanisms of innate immune defense are based on the recognition of invariant microbial molecular patterns by specific receptors, followed by the activation of signaling pathways and the expression of effector molecules that will defeat the invading microorganism. Two recent reports add to the growing list of these pattern-recognition receptors by showing that the intracellular nucleotide-binding oligomerization domain 1 (NOD1) protein recognizes a diaminopimelate-containing muropeptide, a cell-wall component of Gram-negative bacteria. |
Goto, Akira; Blandin, Stéphanie A; Royet, Julien; Reichhart, Jean-Marc; Levashina, Elena A Silencing of Toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies Article de journal Nucleic Acids Res., 31 (22), p. 6619–6623, 2003, ISSN: 1362-4962. Résumé | BibTeX | Étiquettes: Animals, blandin, Cell Surface, Double-Stranded, Epistasis, Female, Genetic, Green Fluorescent Proteins, Homeodomain Proteins, Luminescent Proteins, M3i, Phenotype, Receptors, reichhart, RNA, RNA Interference, Serpins, Signal Transduction, Time Factors, Toll-Like Receptors, Transcription Factors @article{goto_silencing_2003, title = {Silencing of Toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies}, author = {Akira Goto and Stéphanie A Blandin and Julien Royet and Jean-Marc Reichhart and Elena A Levashina}, issn = {1362-4962}, year = {2003}, date = {2003-11-01}, journal = {Nucleic Acids Res.}, volume = {31}, number = {22}, pages = {6619--6623}, abstract = {Double-stranded RNA (dsRNA) gene interference is an efficient method to silence gene expression in a sequence-specific manner. Here we show that the direct injection of dsRNA can be used in adult Drosophila flies to disrupt function of endogenous genes in vivo. As a proof of principle, we have used this method to silence components of a major signaling cascade, the Toll pathway, which controls fruit fly resistance to fungal and Gram-positive bacterial infections. We demonstrate that the knockout is efficient only if dsRNA is injected in 4- or more day-old flies and that it lasts for at least 1 week. Furthermore, we report dsRNA-based epistatic gene analysis via injection of a mixture of two dsRNAs and propose that injection of dsRNA represents a powerful method for rapid functional analysis of genes in Drosophila melanogaster adults, particularly of those whose mutations are lethal during development.}, keywords = {Animals, blandin, Cell Surface, Double-Stranded, Epistasis, Female, Genetic, Green Fluorescent Proteins, Homeodomain Proteins, Luminescent Proteins, M3i, Phenotype, Receptors, reichhart, RNA, RNA Interference, Serpins, Signal Transduction, Time Factors, Toll-Like Receptors, Transcription Factors}, pubstate = {published}, tppubtype = {article} } Double-stranded RNA (dsRNA) gene interference is an efficient method to silence gene expression in a sequence-specific manner. Here we show that the direct injection of dsRNA can be used in adult Drosophila flies to disrupt function of endogenous genes in vivo. As a proof of principle, we have used this method to silence components of a major signaling cascade, the Toll pathway, which controls fruit fly resistance to fungal and Gram-positive bacterial infections. We demonstrate that the knockout is efficient only if dsRNA is injected in 4- or more day-old flies and that it lasts for at least 1 week. Furthermore, we report dsRNA-based epistatic gene analysis via injection of a mixture of two dsRNAs and propose that injection of dsRNA represents a powerful method for rapid functional analysis of genes in Drosophila melanogaster adults, particularly of those whose mutations are lethal during development. |
Hoffmann, Jules A The immune response of Drosophila Article de journal Nature, 426 (6962), p. 33–38, 2003, ISSN: 1476-4687. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Surface, hoffmann, Immunity, Innate, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors @article{hoffmann_immune_2003, title = {The immune response of Drosophila}, author = {Jules A Hoffmann}, doi = {10.1038/nature02021}, issn = {1476-4687}, year = {2003}, date = {2003-11-01}, journal = {Nature}, volume = {426}, number = {6962}, pages = {33--38}, abstract = {Drosophila mounts a potent host defence when challenged by various microorganisms. Analysis of this defence by molecular genetics has now provided a global picture of the mechanisms by which this insect senses infection, discriminates between various classes of microorganisms and induces the production of effector molecules, among which antimicrobial peptides are prominent. An unexpected result of these studies was the discovery that most of the genes involved in the Drosophila host defence are homologous or very similar to genes implicated in mammalian innate immune defences. Recent progress in research on Drosophila immune defence provides evidence for similarities and differences between Drosophila immune responses and mammalian innate immunity.}, keywords = {Animals, Cell Surface, hoffmann, Immunity, Innate, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptor 5, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila mounts a potent host defence when challenged by various microorganisms. Analysis of this defence by molecular genetics has now provided a global picture of the mechanisms by which this insect senses infection, discriminates between various classes of microorganisms and induces the production of effector molecules, among which antimicrobial peptides are prominent. An unexpected result of these studies was the discovery that most of the genes involved in the Drosophila host defence are homologous or very similar to genes implicated in mammalian innate immune defences. Recent progress in research on Drosophila immune defence provides evidence for similarities and differences between Drosophila immune responses and mammalian innate immunity. |
Weber, Alexander N R; Tauszig-Delamasure, Servane; Hoffmann, Jules A; Lelièvre, Eric; Gascan, Hugues; Ray, Keith P; Morse, Mary A; Imler, Jean-Luc; Gay, Nicholas J Binding of the Drosophila cytokine Spätzle to Toll is direct and establishes signaling Article de journal Nature Immunology, 4 (8), p. 794–800, 2003, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Cell Surface, hoffmann, imler, Insect Proteins, M3i, Protein Binding, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors @article{weber_binding_2003, title = {Binding of the Drosophila cytokine Spätzle to Toll is direct and establishes signaling}, author = {Alexander N R Weber and Servane Tauszig-Delamasure and Jules A Hoffmann and Eric Lelièvre and Hugues Gascan and Keith P Ray and Mary A Morse and Jean-Luc Imler and Nicholas J Gay}, doi = {10.1038/ni955}, issn = {1529-2908}, year = {2003}, date = {2003-08-01}, journal = {Nature Immunology}, volume = {4}, number = {8}, pages = {794--800}, abstract = {The extracellular protein Spätzle is required for activation of the Toll signaling pathway in the embryonic development and innate immune defense of Drosophila. Spätzle is synthesized as a pro-protein and is processed to a functional form by a serine protease. We show here that the mature form of Spätzle triggers a Toll-dependent immune response after injection into the hemolymph of flies. Spätzle specifically bound to Drosophila cells and to Cos-7 cells expressing Toll. Furthermore, in vitro experiments showed that the mature form of Spätzle bound to the Toll ectodomain with high affinity and with a stoichiometry of one Spätzle dimer to two receptors. The Spätzle pro-protein was inactive in all these assays, indicating that the pro-domain sequence, which is natively unstructured, acts to prevent interaction of the cytokine and its receptor Toll. These results show that, in contrast to the human Toll-like receptors, Drosophila Toll requires only an endogenous protein ligand for activation and signaling.}, keywords = {Animals, Cell Surface, hoffmann, imler, Insect Proteins, M3i, Protein Binding, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The extracellular protein Spätzle is required for activation of the Toll signaling pathway in the embryonic development and innate immune defense of Drosophila. Spätzle is synthesized as a pro-protein and is processed to a functional form by a serine protease. We show here that the mature form of Spätzle triggers a Toll-dependent immune response after injection into the hemolymph of flies. Spätzle specifically bound to Drosophila cells and to Cos-7 cells expressing Toll. Furthermore, in vitro experiments showed that the mature form of Spätzle bound to the Toll ectodomain with high affinity and with a stoichiometry of one Spätzle dimer to two receptors. The Spätzle pro-protein was inactive in all these assays, indicating that the pro-domain sequence, which is natively unstructured, acts to prevent interaction of the cytokine and its receptor Toll. These results show that, in contrast to the human Toll-like receptors, Drosophila Toll requires only an endogenous protein ligand for activation and signaling. |
Hetru, Charles; Troxler, Laurent; Hoffmann, Jules A Drosophila melanogaster antimicrobial defense Article de journal J. Infect. Dis., 187 Suppl 2 , p. S327–334, 2003, ISSN: 0022-1899. Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Bacterial Infections, bioinformatic, hoffmann, Immunity, Innate, M3i, Mycoses, Parasitic Diseases, Peptides, Signal Transduction @article{hetru_drosophila_2003, title = {Drosophila melanogaster antimicrobial defense}, author = {Charles Hetru and Laurent Troxler and Jules A Hoffmann}, doi = {10.1086/374758}, issn = {0022-1899}, year = {2003}, date = {2003-06-01}, journal = {J. Infect. Dis.}, volume = {187 Suppl 2}, pages = {S327--334}, abstract = {The Drosophila melanogaster host defense is complex but remarkably efficient. It is a multifaceted response to a variety of fungal, bacterial, and parasitic invaders. Current knowledge is discussed on recognition of infectious microorganisms and on the activation of intracellular signaling cascades that concur with the expression of numerous immune-responsive genes, among which, to date, the most prominent appear to encode potent antimicrobial peptides.}, keywords = {Animal, Animals, Bacterial Infections, bioinformatic, hoffmann, Immunity, Innate, M3i, Mycoses, Parasitic Diseases, Peptides, Signal Transduction}, pubstate = {published}, tppubtype = {article} } The Drosophila melanogaster host defense is complex but remarkably efficient. It is a multifaceted response to a variety of fungal, bacterial, and parasitic invaders. Current knowledge is discussed on recognition of infectious microorganisms and on the activation of intracellular signaling cascades that concur with the expression of numerous immune-responsive genes, among which, to date, the most prominent appear to encode potent antimicrobial peptides. |
Luna, C; Hoa, N T; Zhang, J; Kanzok, S M; Brown, S E; Imler, Jean-Luc; Knudson, D L; Zheng, L Characterization of three Toll-like genes from mosquito Aedes aegypti Article de journal Insect Molecular Biology, 12 (1), p. 67–74, 2003, ISSN: 0962-1075. Résumé | BibTeX | Étiquettes: Aedes, Animals, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, imler, Insect Proteins, M3i, Male, messenger, Models, Molecular, Mutagenesis, Promoter Regions, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Sequence Alignment, Signal Transduction, Site-Directed, Transfection @article{luna_characterization_2003, title = {Characterization of three Toll-like genes from mosquito Aedes aegypti}, author = {C Luna and N T Hoa and J Zhang and S M Kanzok and S E Brown and Jean-Luc Imler and D L Knudson and L Zheng}, issn = {0962-1075}, year = {2003}, date = {2003-02-01}, journal = {Insect Molecular Biology}, volume = {12}, number = {1}, pages = {67--74}, abstract = {Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function.}, keywords = {Aedes, Animals, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, imler, Insect Proteins, M3i, Male, messenger, Models, Molecular, Mutagenesis, Promoter Regions, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Sequence Alignment, Signal Transduction, Site-Directed, Transfection}, pubstate = {published}, tppubtype = {article} } Three Toll-related genes (AeToll1A, AeToll1B and AeToll5) were cloned and characterized from the yellow fever vector mosquito, Aedes aegypti. All three genes exhibited high levels of amino acid sequence similarity with Drosophila melanogaster (Dm)Toll1 and DmTehao (Toll5). AeToll1A and AeToll1B are 1124 and 1076 amino acid residues long, respectively. Both contain a carboxyl extension downstream of the Toll/interleukin-1 receptor (TIR) domain. AeToll5 is 1007 residues long and, like DmTehao, lacks the carboxyl terminal extension. Expression of these three genes was examined throughout development and after immune challenge. Both AeToll1A and AeToll5, like their Drosophila counterparts, activate transcription of drosomycin promoter in both Aedes and Drosophila cell lines. Deletion of the carboxyl extension of AeToll1A did not result in a further elevated level of the antifungal response. The intracellular signalling process appears to be species specific based on two observations. (1) DmToll is completely inactive in an Aedes cell line, suggesting a higher specificity requirement for DmToll in the intracellular signalling process. (2) Only one of three amino acid residues essential for DmToll function is required for AeToll1A function. |
Imler, Jean-Luc; Hoffmann, Jules A Toll signaling: the TIReless quest for specificity Article de journal Nature Immunology, 4 (2), p. 105–106, 2003, ISSN: 1529-2908. Liens | BibTeX | Étiquettes: Animals, Cell Surface, Dendritic Cells, hoffmann, Humans, imler, Immunological, Interferon-beta, M3i, Membrane Glycoproteins, Mice, Models, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors @article{imler_toll_2003, title = {Toll signaling: the TIReless quest for specificity}, author = {Jean-Luc Imler and Jules A Hoffmann}, doi = {10.1038/ni0203-105}, issn = {1529-2908}, year = {2003}, date = {2003-02-01}, journal = {Nature Immunology}, volume = {4}, number = {2}, pages = {105--106}, keywords = {Animals, Cell Surface, Dendritic Cells, hoffmann, Humans, imler, Immunological, Interferon-beta, M3i, Membrane Glycoproteins, Mice, Models, Protein Structure, Receptors, Signal Transduction, Tertiary, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } |
2002 |
Duvic, Bernard; Hoffmann, Jules A; Meister, Marie; Royet, Julien Notch signaling controls lineage specification during Drosophila larval hematopoiesis Article de journal Curr. Biol., 12 (22), p. 1923–1927, 2002, ISSN: 0960-9822. Résumé | BibTeX | Étiquettes: Animals, Cell Differentiation, Hematopoiesis, hoffmann, Larva, Lymphoid Tissue, M3i, Membrane Proteins, Notch, Receptors, Signal Transduction @article{duvic_notch_2002, title = {Notch signaling controls lineage specification during Drosophila larval hematopoiesis}, author = {Bernard Duvic and Jules A Hoffmann and Marie Meister and Julien Royet}, issn = {0960-9822}, year = {2002}, date = {2002-11-01}, journal = {Curr. Biol.}, volume = {12}, number = {22}, pages = {1923--1927}, abstract = {Drosophila larval hemocytes originate from a hematopoietic organ called lymph glands, which are composed of paired lobes located along the dorsal vessel. Two mature blood cell populations are found in the circulating hemolymph: the macrophage-like plasmatocytes, and the crystal cells that contain enzymes of the immune-related melanization process. A third class of cells, called lamellocytes, are normally absent in larvae but differentiate after infection by parasites too large to be phagocytosed. Here we present evidence that the Notch signaling pathway plays an instructive role in the differentiation of crystal cells. Loss-of-function mutations in Notch result in severely decreased crystal cell numbers, whereas overexpression of Notch provokes the differentiation of high numbers of these cells. We demonstrate that, in this process, Serrate, not Delta, is the Notch ligand. In addition, Notch function is necessary for lamellocyte proliferation upon parasitization, although Notch overexpression does not result in lamellocyte production. Finally, Notch does not appear to play a role in the differentiation of the plasmatocyte lineage. This study underlines the existence of parallels in the genetic control of hematopoiesis in Drosophila and in mammals.}, keywords = {Animals, Cell Differentiation, Hematopoiesis, hoffmann, Larva, Lymphoid Tissue, M3i, Membrane Proteins, Notch, Receptors, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Drosophila larval hemocytes originate from a hematopoietic organ called lymph glands, which are composed of paired lobes located along the dorsal vessel. Two mature blood cell populations are found in the circulating hemolymph: the macrophage-like plasmatocytes, and the crystal cells that contain enzymes of the immune-related melanization process. A third class of cells, called lamellocytes, are normally absent in larvae but differentiate after infection by parasites too large to be phagocytosed. Here we present evidence that the Notch signaling pathway plays an instructive role in the differentiation of crystal cells. Loss-of-function mutations in Notch result in severely decreased crystal cell numbers, whereas overexpression of Notch provokes the differentiation of high numbers of these cells. We demonstrate that, in this process, Serrate, not Delta, is the Notch ligand. In addition, Notch function is necessary for lamellocyte proliferation upon parasitization, although Notch overexpression does not result in lamellocyte production. Finally, Notch does not appear to play a role in the differentiation of the plasmatocyte lineage. This study underlines the existence of parallels in the genetic control of hematopoiesis in Drosophila and in mammals. |
Naitza, Silvia; Rossé, Carine; Kappler, Christine; Georgel, Philippe; Belvin, Marcia; Gubb, David; Camonis, Jacques; Hoffmann, Jules A; Reichhart, Jean-Marc The Drosophila immune defense against gram-negative infection requires the death protein dFADD Article de journal Immunity, 17 (5), p. 575–581, 2002, ISSN: 1074-7613. Résumé | BibTeX | Étiquettes: Adaptor Proteins, Animals, Carrier Proteins, Fas-Associated Death Domain Protein, Gene Expression Regulation, Gram-Negative Bacterial Infections, hoffmann, Immunity, M3i, reichhart, Signal Transducing, Signal Transduction @article{naitza_drosophila_2002, title = {The Drosophila immune defense against gram-negative infection requires the death protein dFADD}, author = {Silvia Naitza and Carine Rossé and Christine Kappler and Philippe Georgel and Marcia Belvin and David Gubb and Jacques Camonis and Jules A Hoffmann and Jean-Marc Reichhart}, issn = {1074-7613}, year = {2002}, date = {2002-11-01}, journal = {Immunity}, volume = {17}, number = {5}, pages = {575--581}, abstract = {Drosophila responds to Gram-negative infections by mounting an immune response that depends on components of the IMD pathway. We recently showed that imd encodes a protein with a death domain with high similarity to that of mammalian RIP. Using a two-hybrid screen in yeast, we have isolated the death protein dFADD as a molecule that associates with IMD. Our data show that loss of dFADD function renders flies highly susceptible to Gram-negative infections without affecting resistance to Gram-positive bacteria. By genetic analysis we show that dFADD acts downstream of IMD in the pathway that controls inducibility of the antibacterial peptide genes.}, keywords = {Adaptor Proteins, Animals, Carrier Proteins, Fas-Associated Death Domain Protein, Gene Expression Regulation, Gram-Negative Bacterial Infections, hoffmann, Immunity, M3i, reichhart, Signal Transducing, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Drosophila responds to Gram-negative infections by mounting an immune response that depends on components of the IMD pathway. We recently showed that imd encodes a protein with a death domain with high similarity to that of mammalian RIP. Using a two-hybrid screen in yeast, we have isolated the death protein dFADD as a molecule that associates with IMD. Our data show that loss of dFADD function renders flies highly susceptible to Gram-negative infections without affecting resistance to Gram-positive bacteria. By genetic analysis we show that dFADD acts downstream of IMD in the pathway that controls inducibility of the antibacterial peptide genes. |
Christophides, George K; Zdobnov, Evgeny; Barillas-Mury, Carolina; Birney, Ewan; Blandin, Stephanie A; Blass, Claudia; Brey, Paul T; Collins, Frank H; Danielli, Alberto; Dimopoulos, George; Hetru, Charles; Hoa, Ngo T; Hoffmann, Jules A; Kanzok, Stefan M; Letunic, Ivica; Levashina, Elena A; Loukeris, Thanasis G; Lycett, Gareth; Meister, Stephan; Michel, Kristin; Moita, Luis F; Müller, Hans-Michael; Osta, Mike A; Paskewitz, Susan M; Reichhart, Jean-Marc; Rzhetsky, Andrey; Troxler, Laurent; Vernick, Kenneth D; Vlachou, Dina; Volz, Jennifer; von Mering, Christian; Xu, Jiannong; Zheng, Liangbiao; Bork, Peer; Kafatos, Fotis C Immunity-related genes and gene families in Anopheles gambiae Article de journal Science, 298 (5591), p. 159–165, 2002, ISSN: 1095-9203. Résumé | Liens | BibTeX | Étiquettes: Alternative Splicing, Animals, Anopheles, Apoptosis, bacteria, bioinformatic, blandin, Catechol Oxidase, Computational Biology, Enzyme Precursors, Gene Expression Regulation, Genes, Genetic, Genome, hoffmann, Immunity, Innate, Insect, Insect Proteins, M3i, Multigene Family, Peptides, Phylogeny, Plasmodium, Protein Structure, reichhart, Selection, Serine Endopeptidases, Serpins, Signal Transduction, Tertiary @article{christophides_immunity-related_2002, title = {Immunity-related genes and gene families in Anopheles gambiae}, author = {George K Christophides and Evgeny Zdobnov and Carolina Barillas-Mury and Ewan Birney and Stephanie A Blandin and Claudia Blass and Paul T Brey and Frank H Collins and Alberto Danielli and George Dimopoulos and Charles Hetru and Ngo T Hoa and Jules A Hoffmann and Stefan M Kanzok and Ivica Letunic and Elena A Levashina and Thanasis G Loukeris and Gareth Lycett and Stephan Meister and Kristin Michel and Luis F Moita and Hans-Michael Müller and Mike A Osta and Susan M Paskewitz and Jean-Marc Reichhart and Andrey Rzhetsky and Laurent Troxler and Kenneth D Vernick and Dina Vlachou and Jennifer Volz and Christian von Mering and Jiannong Xu and Liangbiao Zheng and Peer Bork and Fotis C Kafatos}, url = {http://www.ncbi.nlm.nih.gov/pubmed/12364793}, doi = {10.1126/science.1077136}, issn = {1095-9203}, year = {2002}, date = {2002-10-01}, journal = {Science}, volume = {298}, number = {5591}, pages = {159--165}, abstract = {We have identified 242 Anopheles gambiae genes from 18 gene families implicated in innate immunity and have detected marked diversification relative to Drosophila melanogaster. Immune-related gene families involved in recognition, signal modulation, and effector systems show a marked deficit of orthologs and excessive gene expansions, possibly reflecting selection pressures from different pathogens encountered in these insects' very different life-styles. In contrast, the multifunctional Toll signal transduction pathway is substantially conserved, presumably because of counterselection for developmental stability. Representative expression profiles confirm that sequence diversification is accompanied by specific responses to different immune challenges. Alternative RNA splicing may also contribute to expansion of the immune repertoire.}, keywords = {Alternative Splicing, Animals, Anopheles, Apoptosis, bacteria, bioinformatic, blandin, Catechol Oxidase, Computational Biology, Enzyme Precursors, Gene Expression Regulation, Genes, Genetic, Genome, hoffmann, Immunity, Innate, Insect, Insect Proteins, M3i, Multigene Family, Peptides, Phylogeny, Plasmodium, Protein Structure, reichhart, Selection, Serine Endopeptidases, Serpins, Signal Transduction, Tertiary}, pubstate = {published}, tppubtype = {article} } We have identified 242 Anopheles gambiae genes from 18 gene families implicated in innate immunity and have detected marked diversification relative to Drosophila melanogaster. Immune-related gene families involved in recognition, signal modulation, and effector systems show a marked deficit of orthologs and excessive gene expansions, possibly reflecting selection pressures from different pathogens encountered in these insects' very different life-styles. In contrast, the multifunctional Toll signal transduction pathway is substantially conserved, presumably because of counterselection for developmental stability. Representative expression profiles confirm that sequence diversification is accompanied by specific responses to different immune challenges. Alternative RNA splicing may also contribute to expansion of the immune repertoire. |
Gottar, Marie; Gobert, Vanessa; Michel, Tatiana; Belvin, Marcia; Duyk, Geoffrey; Hoffmann, Jules A; Ferrandon, Dominique; Royet, Julien The Drosophila immune response against Gram-negative bacteria is mediated by a peptidoglycan recognition protein Article de journal Nature, 416 , p. 640–644, 2002, ISBN: 0028-0836. Résumé | Liens | BibTeX | Étiquettes: Animal, Anti-Infective Agents/metabolism, Carrier Proteins/biosynthesis/genetics/*immunology, Drosophila melanogaster/genetics/*immunology/*microbiology, Drosophila Proteins/genetics/metabolism, Epistasis, Female, ferrandon, Genes, Genetic, Genetic Predisposition to Disease, Gram-Negative Bacteria/*immunology/physiology, hoffmann, Human, Insect/genetics, M3i, Messenger/genetics/metabolism, Mutation, Non-U.S. Gov't, P.H.S., Phenotype, RNA, Signal Transduction, Support, Survival Rate, Transgenes/genetics, U.S. Gov't @article{gottar_drosophila_2002b, title = {The Drosophila immune response against Gram-negative bacteria is mediated by a peptidoglycan recognition protein}, author = {Marie Gottar and Vanessa Gobert and Tatiana Michel and Marcia Belvin and Geoffrey Duyk and Jules A Hoffmann and Dominique Ferrandon and Julien Royet}, doi = {10.1038/nature734}, isbn = {0028-0836}, year = {2002}, date = {2002-03-01}, journal = {Nature}, volume = {416}, pages = {640--644}, abstract = {The antimicrobial defence of Drosophila relies largely on the challenge-induced synthesis of an array of potent antimicrobial peptides by the fat body. The defence against Gram-positive bacteria and natural fungal infections is mediated by the Toll signalling pathway, whereas defence against Gram-negative bacteria is dependent on the Immune deficiency (IMD) pathway. Loss-of-function mutations in either pathway reduce the resistance to corresponding infections. The link between microbial infections and activation of these two pathways has remained elusive. The Toll pathway is activated by Gram-positive bacteria through a circulating Peptidoglycan recognition protein (PGRP-SA). PGRPs appear to be highly conserved from insects to mammals, and the Drosophila genome contains 13 members. Here we report a mutation in a gene coding for a putative transmembrane protein, PGRP-LC, which reduces survival to Gram-negative sepsis but has no effect on the response to Gram-positive bacteria or natural fungal infections. By genetic epistasis, we demonstrate that PGRP-LC acts upstream of the imd gene. The data on PGRP-SA with respect to the response to Gram-positive infections, together with the present report, indicate that the PGRP family has a principal role in sensing microbial infections in Drosophila.}, keywords = {Animal, Anti-Infective Agents/metabolism, Carrier Proteins/biosynthesis/genetics/*immunology, Drosophila melanogaster/genetics/*immunology/*microbiology, Drosophila Proteins/genetics/metabolism, Epistasis, Female, ferrandon, Genes, Genetic, Genetic Predisposition to Disease, Gram-Negative Bacteria/*immunology/physiology, hoffmann, Human, Insect/genetics, M3i, Messenger/genetics/metabolism, Mutation, Non-U.S. Gov't, P.H.S., Phenotype, RNA, Signal Transduction, Support, Survival Rate, Transgenes/genetics, U.S. Gov't}, pubstate = {published}, tppubtype = {article} } The antimicrobial defence of Drosophila relies largely on the challenge-induced synthesis of an array of potent antimicrobial peptides by the fat body. The defence against Gram-positive bacteria and natural fungal infections is mediated by the Toll signalling pathway, whereas defence against Gram-negative bacteria is dependent on the Immune deficiency (IMD) pathway. Loss-of-function mutations in either pathway reduce the resistance to corresponding infections. The link between microbial infections and activation of these two pathways has remained elusive. The Toll pathway is activated by Gram-positive bacteria through a circulating Peptidoglycan recognition protein (PGRP-SA). PGRPs appear to be highly conserved from insects to mammals, and the Drosophila genome contains 13 members. Here we report a mutation in a gene coding for a putative transmembrane protein, PGRP-LC, which reduces survival to Gram-negative sepsis but has no effect on the response to Gram-positive bacteria or natural fungal infections. By genetic epistasis, we demonstrate that PGRP-LC acts upstream of the imd gene. The data on PGRP-SA with respect to the response to Gram-positive infections, together with the present report, indicate that the PGRP family has a principal role in sensing microbial infections in Drosophila. |
Hoffmann, Jules A; Reichhart, Jean-Marc Drosophila innate immunity: an evolutionary perspective Article de journal Nat. Immunol., 3 (2), p. 121–126, 2002, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological Evolution, Cell Surface, hoffmann, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors @article{hoffmann_drosophila_2002, title = {Drosophila innate immunity: an evolutionary perspective}, author = {Jules A Hoffmann and Jean-Marc Reichhart}, doi = {10.1038/ni0202-121}, issn = {1529-2908}, year = {2002}, date = {2002-02-01}, journal = {Nat. Immunol.}, volume = {3}, number = {2}, pages = {121--126}, abstract = {In response to microbial infections, Drosophila mounts a multifaceted immune response involving humoral reactions that culminate in the destruction of invading organisms by lytic peptides. These defense mechanisms are activated via two distinct signaling pathways. One of these, the Toll pathway, controls resistance to fungal and Gram-positive bacterial infections, whereas the Imd pathway is responsible for defense against Gram-negative bacterial infections. Current evidence indicates that recognition of infectious nonself agents results from interactions between microbial wall components and extracellular pattern recognition proteins. We discuss here evolutionary perspectives on our present understanding of the antimicrobial defenses of Drosophila.}, keywords = {Animals, Biological Evolution, Cell Surface, hoffmann, Immunity, Immunological, Innate, M3i, Membrane Glycoproteins, Models, Receptors, reichhart, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } In response to microbial infections, Drosophila mounts a multifaceted immune response involving humoral reactions that culminate in the destruction of invading organisms by lytic peptides. These defense mechanisms are activated via two distinct signaling pathways. One of these, the Toll pathway, controls resistance to fungal and Gram-positive bacterial infections, whereas the Imd pathway is responsible for defense against Gram-negative bacterial infections. Current evidence indicates that recognition of infectious nonself agents results from interactions between microbial wall components and extracellular pattern recognition proteins. We discuss here evolutionary perspectives on our present understanding of the antimicrobial defenses of Drosophila. |
Imler, Jean-Luc; Hoffmann, Jules A Toll receptors in Drosophila: a family of molecules regulating development and immunity Article de journal Current Topics in Microbiology and Immunology, 270 , p. 63–79, 2002, ISSN: 0070-217X. Résumé | BibTeX | Étiquettes: Animals, Cell Surface, Genetic, Gram-Negative Bacteria, hoffmann, imler, M3i, Receptors, Signal Transduction, Toll-Like Receptors, Transcription @article{imler_toll_2002, title = {Toll receptors in Drosophila: a family of molecules regulating development and immunity}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {0070-217X}, year = {2002}, date = {2002-01-01}, journal = {Current Topics in Microbiology and Immunology}, volume = {270}, pages = {63--79}, abstract = {In recent years, Toll-like receptors (TLRs) have emerged as key receptors which detect microbes and initiate an inflammatory response. The Toll receptor was originally identified and characterized 14 years ago for its role in the embryonic development of the fruit-fly Drosophila melanogaster. Subsequently, it was also shown to be an essential component of the signaling pathway mediating the anti-fungal host defense in this model organism. New factors involved in the activation of the Toll receptor or in intracytoplasmic signaling during the immune response in Drosophila have recently been identified. The existence of significant functional differences between mammalian TLRs and Drosophila Toll receptors is also becoming apparent.}, keywords = {Animals, Cell Surface, Genetic, Gram-Negative Bacteria, hoffmann, imler, M3i, Receptors, Signal Transduction, Toll-Like Receptors, Transcription}, pubstate = {published}, tppubtype = {article} } In recent years, Toll-like receptors (TLRs) have emerged as key receptors which detect microbes and initiate an inflammatory response. The Toll receptor was originally identified and characterized 14 years ago for its role in the embryonic development of the fruit-fly Drosophila melanogaster. Subsequently, it was also shown to be an essential component of the signaling pathway mediating the anti-fungal host defense in this model organism. New factors involved in the activation of the Toll receptor or in intracytoplasmic signaling during the immune response in Drosophila have recently been identified. The existence of significant functional differences between mammalian TLRs and Drosophila Toll receptors is also becoming apparent. |
2001 |
Irving, Phil; Troxler, Laurent; Heuer, Timothy S; Belvin, Marcia; Kopczynski, Casey; Reichhart, Jean-Marc; Hoffmann, Jules A; Hetru, Charles A genome-wide analysis of immune responses in Drosophila Article de journal Proc. Natl. Acad. Sci. U.S.A., 98 (26), p. 15119–15124, 2001, ISSN: 0027-8424. Résumé | Liens | BibTeX | Étiquettes: Animals, bioinformatic, Gene Expression Regulation, Genome, Gram-Negative Bacteria, hoffmann, M3i, Male, Oligonucleotide Array Sequence Analysis, reichhart, Signal Transduction @article{irving_genome-wide_2001, title = {A genome-wide analysis of immune responses in Drosophila}, author = {Phil Irving and Laurent Troxler and Timothy S Heuer and Marcia Belvin and Casey Kopczynski and Jean-Marc Reichhart and Jules A Hoffmann and Charles Hetru}, doi = {10.1073/pnas.261573998}, issn = {0027-8424}, year = {2001}, date = {2001-12-01}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, volume = {98}, number = {26}, pages = {15119--15124}, abstract = {Oligonucleotide DNA microarrays were used for a genome-wide analysis of immune-challenged Drosophila infected with Gram-positive or Gram-negative bacteria, or with fungi. Aside from the expression of an established set of immune defense genes, a significant number of previously unseen immune-induced genes were found. Genes of particular interest include corin- and Stubble-like genes, both of which have a type II transmembrane domain; easter- and snake-like genes, which may fulfil the roles of easter and snake in the Toll pathway; and a masquerade-like gene, potentially involved in enzyme regulation. The microarray data has also helped to greatly reduce the number of target genes in large gene groups, such as the proteases, helping to direct the choices for future mutant studies. Many of the up-regulated genes fit into the current conceptual framework of host defense, whereas others, including the substantial number of genes with unknown functions, offer new avenues for research.}, keywords = {Animals, bioinformatic, Gene Expression Regulation, Genome, Gram-Negative Bacteria, hoffmann, M3i, Male, Oligonucleotide Array Sequence Analysis, reichhart, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Oligonucleotide DNA microarrays were used for a genome-wide analysis of immune-challenged Drosophila infected with Gram-positive or Gram-negative bacteria, or with fungi. Aside from the expression of an established set of immune defense genes, a significant number of previously unseen immune-induced genes were found. Genes of particular interest include corin- and Stubble-like genes, both of which have a type II transmembrane domain; easter- and snake-like genes, which may fulfil the roles of easter and snake in the Toll pathway; and a masquerade-like gene, potentially involved in enzyme regulation. The microarray data has also helped to greatly reduce the number of target genes in large gene groups, such as the proteases, helping to direct the choices for future mutant studies. Many of the up-regulated genes fit into the current conceptual framework of host defense, whereas others, including the substantial number of genes with unknown functions, offer new avenues for research. |
2000 |
Rutschmann, Sophie; Jung, Alain C; Zhou, R; Silverman, N; Hoffmann, Jules A; Ferrandon, Dominique Role of Drosophila IKK gamma in a toll-independent antibacterial immune response Article de journal Nat. Immunol., 1 (4), p. 342–347, 2000, ISSN: 1529-2908. Résumé | Liens | BibTeX | Étiquettes: Animals, Antigens, Bacterial, Cell Surface, ferrandon, Gene Expression Regulation, hoffmann, I-kappa B Kinase, Immunity, Innate, Insect Proteins, M3i, Membrane Glycoproteins, Protein-Serine-Threonine Kinases, Receptors, Signal Transduction, Toll-Like Receptors, Transcription Factors @article{rutschmann_role_2000, title = {Role of Drosophila IKK gamma in a toll-independent antibacterial immune response}, author = {Sophie Rutschmann and Alain C Jung and R Zhou and N Silverman and Jules A Hoffmann and Dominique Ferrandon}, doi = {10.1038/79801}, issn = {1529-2908}, year = {2000}, date = {2000-10-01}, journal = {Nat. Immunol.}, volume = {1}, number = {4}, pages = {342--347}, abstract = {We have generated, by ethylmethane sulfonate mutagenesis, loss-of-function mutants in the Drosophila homolog of the mammalian I-kappa B kinase (IKK) complex component IKK gamma (also called NEMO). Our data show that Drosophila IKK gamma is required for the Relish-dependent immune induction of the genes encoding antibacterial peptides and for resistance to infections by Escherichia coli. However, it is not required for the Toll-DIF-dependent antifungal host defense. The results indicate distinct control mechanisms of the Rel-like transactivators DIF and Relish in the Drosophila innate immune response and show that Drosophila Toll does not signal through a IKK gamma-dependent signaling complex. Thus, in contrast to the vertebrate inflammatory response, IKK gamma is required for the activation of only one immune signaling pathway in Drosophila.}, keywords = {Animals, Antigens, Bacterial, Cell Surface, ferrandon, Gene Expression Regulation, hoffmann, I-kappa B Kinase, Immunity, Innate, Insect Proteins, M3i, Membrane Glycoproteins, Protein-Serine-Threonine Kinases, Receptors, Signal Transduction, Toll-Like Receptors, Transcription Factors}, pubstate = {published}, tppubtype = {article} } We have generated, by ethylmethane sulfonate mutagenesis, loss-of-function mutants in the Drosophila homolog of the mammalian I-kappa B kinase (IKK) complex component IKK gamma (also called NEMO). Our data show that Drosophila IKK gamma is required for the Relish-dependent immune induction of the genes encoding antibacterial peptides and for resistance to infections by Escherichia coli. However, it is not required for the Toll-DIF-dependent antifungal host defense. The results indicate distinct control mechanisms of the Rel-like transactivators DIF and Relish in the Drosophila innate immune response and show that Drosophila Toll does not signal through a IKK gamma-dependent signaling complex. Thus, in contrast to the vertebrate inflammatory response, IKK gamma is required for the activation of only one immune signaling pathway in Drosophila. |
Imler, Jean-Luc; Hoffmann, Jules A Signaling mechanisms in the antimicrobial host defense of Drosophila Article de journal Current Opinion in Microbiology, 3 (1), p. 16–22, 2000, ISSN: 1369-5274. Résumé | BibTeX | Étiquettes: Animals, Anti-Infective Agents, Cell Surface, Gene Expression Regulation, Genes, hoffmann, imler, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptors @article{imler_signaling_2000, title = {Signaling mechanisms in the antimicrobial host defense of Drosophila}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {1369-5274}, year = {2000}, date = {2000-02-01}, journal = {Current Opinion in Microbiology}, volume = {3}, number = {1}, pages = {16--22}, abstract = {Drosophila has appeared in recent years as a powerful model to study innate immunity. Several papers published in the past year shed light on the role of the three Rel proteins Dorsal, Dif and Relish in the regulation of antimicrobial peptide expression. In addition, the discovery that a blood serine protease inhibitor is involved in the control of the antifungal response indicates that Toll is activated upon triggering of a proteolytic cascade and does not function as a Drosophila pattern recognition receptor.}, keywords = {Animals, Anti-Infective Agents, Cell Surface, Gene Expression Regulation, Genes, hoffmann, imler, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Receptors, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } Drosophila has appeared in recent years as a powerful model to study innate immunity. Several papers published in the past year shed light on the role of the three Rel proteins Dorsal, Dif and Relish in the regulation of antimicrobial peptide expression. In addition, the discovery that a blood serine protease inhibitor is involved in the control of the antifungal response indicates that Toll is activated upon triggering of a proteolytic cascade and does not function as a Drosophila pattern recognition receptor. |
Imler, Jean-Luc; Tauszig, Servane; Jouanguy, Emmanuelle; Forestier, C; Hoffmann, Jules A LPS-induced immune response in Drosophila Article de journal Journal of Endotoxin Research, 6 (6), p. 459–462, 2000, ISSN: 0968-0519. Résumé | BibTeX | Étiquettes: Animals, Biological, Cell Line, Cell Surface, Defensins, Genes, Genetic, hoffmann, imler, Insect, Insect Proteins, Lipopolysaccharides, M3i, Membrane Glycoproteins, Models, Mutation, Promoter Regions, Receptors, Signal Transduction, Toll-Like Receptors @article{imler_lps-induced_2000, title = {LPS-induced immune response in Drosophila}, author = {Jean-Luc Imler and Servane Tauszig and Emmanuelle Jouanguy and C Forestier and Jules A Hoffmann}, issn = {0968-0519}, year = {2000}, date = {2000-01-01}, journal = {Journal of Endotoxin Research}, volume = {6}, number = {6}, pages = {459--462}, abstract = {The study of the regulation of the inducible synthesis of antimicrobial peptides in Drosophila melanogaster has established this insect as a powerful model in which to study innate immunity. In particular, the molecular characterization of the regulatory pathway controlling the antifungal peptide drosomycin has revealed the importance of Toll receptors in innate immunity. We report here that injection of LPS into flies induces an immune response, suggesting that LPS receptors are used in Drosophila to detect Gram-negative bacteria infection. We have identified in the recently sequenced genome of Drosophila eight genes coding for Toll-like receptors in addition to Toll, which may function as LPS receptors. However, overexpression of a selection of these genes in tissue-culture cells does not result in up-regulation of the antibacterial peptide genes. These results are discussed in light of the recent data from genetic screens aimed at identifying the genes controlling the antibacterial response in Drosophila.}, keywords = {Animals, Biological, Cell Line, Cell Surface, Defensins, Genes, Genetic, hoffmann, imler, Insect, Insect Proteins, Lipopolysaccharides, M3i, Membrane Glycoproteins, Models, Mutation, Promoter Regions, Receptors, Signal Transduction, Toll-Like Receptors}, pubstate = {published}, tppubtype = {article} } The study of the regulation of the inducible synthesis of antimicrobial peptides in Drosophila melanogaster has established this insect as a powerful model in which to study innate immunity. In particular, the molecular characterization of the regulatory pathway controlling the antifungal peptide drosomycin has revealed the importance of Toll receptors in innate immunity. We report here that injection of LPS into flies induces an immune response, suggesting that LPS receptors are used in Drosophila to detect Gram-negative bacteria infection. We have identified in the recently sequenced genome of Drosophila eight genes coding for Toll-like receptors in addition to Toll, which may function as LPS receptors. However, overexpression of a selection of these genes in tissue-culture cells does not result in up-regulation of the antibacterial peptide genes. These results are discussed in light of the recent data from genetic screens aimed at identifying the genes controlling the antibacterial response in Drosophila. |
Imler, Jean-Luc; Hoffmann, Jules A Toll and Toll-like proteins: an ancient family of receptors signaling infection Article de journal Reviews in Immunogenetics, 2 (3), p. 294–304, 2000, ISSN: 1398-1714. Résumé | BibTeX | Étiquettes: Adaptor Proteins, Animals, Antigens, Autoantigens, CD14, Cell Adhesion Molecules, Cell Surface, Differentiation, DNA-Binding Proteins, Gene Expression Regulation, hoffmann, I-kappa B Proteins, imler, Immunity, Immunologic, infection, Innate, Insect Proteins, Interleukin-1 Receptor-Associated Kinases, Knockout, Larva, Lipopolysaccharides, M3i, Mammals, MAP Kinase Signaling System, Membrane Glycoproteins, Membrane Proteins, Mice, Multigene Family, Myeloid Differentiation Factor 88, NF-kappa B, peptidoglycan, Phosphorylation, Post-Translational, Protein Kinases, Protein Processing, Protein Structure, Receptors, Recombinant Fusion Proteins, Signal Transducing, Signal Transduction, Teichoic Acids, Tertiary, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptor 6, Toll-Like Receptor 9, Toll-Like Receptors, Ubiquitins @article{imler_toll_2000, title = {Toll and Toll-like proteins: an ancient family of receptors signaling infection}, author = {Jean-Luc Imler and Jules A Hoffmann}, issn = {1398-1714}, year = {2000}, date = {2000-01-01}, journal = {Reviews in Immunogenetics}, volume = {2}, number = {3}, pages = {294--304}, abstract = {Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to microbes. It involves intracellular signaling pathways in the fruit-fly Drosophila and in mammals that show striking similarities. Recent genetic and biochemical data have revealed, in particular, that proteins of the Toll family play a critical role in the immediate response to infection. We review here the recent developments on the structural and functional characterization of this evolutionary ancient and important family of proteins, which can function as cytokine receptors (Toll in Drosophila) or pattern recognition receptors (TLR4 in mammals) and activate similar, albeit non identical signal transduction pathways, in flies and mammals.}, keywords = {Adaptor Proteins, Animals, Antigens, Autoantigens, CD14, Cell Adhesion Molecules, Cell Surface, Differentiation, DNA-Binding Proteins, Gene Expression Regulation, hoffmann, I-kappa B Proteins, imler, Immunity, Immunologic, infection, Innate, Insect Proteins, Interleukin-1 Receptor-Associated Kinases, Knockout, Larva, Lipopolysaccharides, M3i, Mammals, MAP Kinase Signaling System, Membrane Glycoproteins, Membrane Proteins, Mice, Multigene Family, Myeloid Differentiation Factor 88, NF-kappa B, peptidoglycan, Phosphorylation, Post-Translational, Protein Kinases, Protein Processing, Protein Structure, Receptors, Recombinant Fusion Proteins, Signal Transducing, Signal Transduction, Teichoic Acids, Tertiary, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptor 6, Toll-Like Receptor 9, Toll-Like Receptors, Ubiquitins}, pubstate = {published}, tppubtype = {article} } Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to microbes. It involves intracellular signaling pathways in the fruit-fly Drosophila and in mammals that show striking similarities. Recent genetic and biochemical data have revealed, in particular, that proteins of the Toll family play a critical role in the immediate response to infection. We review here the recent developments on the structural and functional characterization of this evolutionary ancient and important family of proteins, which can function as cytokine receptors (Toll in Drosophila) or pattern recognition receptors (TLR4 in mammals) and activate similar, albeit non identical signal transduction pathways, in flies and mammals. |
1999 |
Levashina, Elena A; Langley, E; Green, C; Gubb, David; Ashburner, M; Hoffmann, Jules A; Reichhart, Jean-Marc Constitutive activation of toll-mediated antifungal defense in serpin-deficient Drosophila Article de journal Science, 285 (5435), p. 1917–1919, 1999, ISSN: 0036-8075. Résumé | BibTeX | Étiquettes: Animals, Antifungal Agents, Antimicrobial Cationic Peptides, Body Patterning, Cell Surface, Escherichia coli, Genes, Hemolymph, hoffmann, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Mutagenesis, Peptides, Receptors, Recombinant Fusion Proteins, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors, Up-Regulation @article{levashina_constitutive_1999, title = {Constitutive activation of toll-mediated antifungal defense in serpin-deficient Drosophila}, author = {Elena A Levashina and E Langley and C Green and David Gubb and M Ashburner and Jules A Hoffmann and Jean-Marc Reichhart}, issn = {0036-8075}, year = {1999}, date = {1999-09-01}, journal = {Science}, volume = {285}, number = {5435}, pages = {1917--1919}, abstract = {The antifungal defense of Drosophila is controlled by the spaetzle/Toll/cactus gene cassette. Here, a loss-of-function mutation in the gene encoding a blood serine protease inhibitor, Spn43Ac, was shown to lead to constitutive expression of the antifungal peptide drosomycin, and this effect was mediated by the spaetzle and Toll gene products. Spaetzle was cleaved by proteolytic enzymes to its active ligand form shortly after immune challenge, and cleaved Spaetzle was constitutively present in Spn43Ac-deficient flies. Hence, Spn43Ac negatively regulates the Toll signaling pathway, and Toll does not function as a pattern recognition receptor in the Drosophila host defense.}, keywords = {Animals, Antifungal Agents, Antimicrobial Cationic Peptides, Body Patterning, Cell Surface, Escherichia coli, Genes, Hemolymph, hoffmann, Insect, Insect Proteins, M3i, Membrane Glycoproteins, Micrococcus luteus, Mutagenesis, Peptides, Receptors, Recombinant Fusion Proteins, reichhart, Serine Proteinase Inhibitors, Serpins, Signal Transduction, Toll-Like Receptors, Up-Regulation}, pubstate = {published}, tppubtype = {article} } The antifungal defense of Drosophila is controlled by the spaetzle/Toll/cactus gene cassette. Here, a loss-of-function mutation in the gene encoding a blood serine protease inhibitor, Spn43Ac, was shown to lead to constitutive expression of the antifungal peptide drosomycin, and this effect was mediated by the spaetzle and Toll gene products. Spaetzle was cleaved by proteolytic enzymes to its active ligand form shortly after immune challenge, and cleaved Spaetzle was constitutively present in Spn43Ac-deficient flies. Hence, Spn43Ac negatively regulates the Toll signaling pathway, and Toll does not function as a pattern recognition receptor in the Drosophila host defense. |