Publications
2007 |
Nehme, Nadine T; Liégeois, Samuel; Kele, Beatrix; Giammarinaro, Philippe; Pradel, Elizabeth; Hoffmann, Jules A; Ewbank, Jonathan J; Ferrandon, Dominique A model of bacterial intestinal infections in Drosophila melanogaster Article de journal PLoS Pathog., 3 (11), p. e173, 2007, ISSN: 1553-7374. Résumé | Liens | BibTeX | Étiquettes: Animal, Animals, Disease Models, Electron, ferrandon, fluorescence, Hemolymph, hoffmann, Host-Pathogen Interactions, Immunohistochemistry, Intestines, M3i, Microscopy, Reverse Transcriptase Polymerase Chain Reaction, Serratia Infections, Serratia marcescens, Transmission @article{nehme_model_2007b, title = {A model of bacterial intestinal infections in Drosophila melanogaster}, author = {Nadine T Nehme and Samuel Liégeois and Beatrix Kele and Philippe Giammarinaro and Elizabeth Pradel and Jules A Hoffmann and Jonathan J Ewbank and Dominique Ferrandon}, doi = {10.1371/journal.ppat.0030173}, issn = {1553-7374}, year = {2007}, date = {2007-01-01}, journal = {PLoS Pathog.}, volume = {3}, number = {11}, pages = {e173}, abstract = {Serratia marcescens is an entomopathogenic bacterium that opportunistically infects a wide range of hosts, including humans. In a model of septic injury, if directly introduced into the body cavity of Drosophila, this pathogen is insensitive to the host's systemic immune response and kills flies in a day. We find that S. marcescens resistance to the Drosophila immune deficiency (imd)-mediated humoral response requires the bacterial lipopolysaccharide O-antigen. If ingested by Drosophila, bacteria cross the gut and penetrate the body cavity. During this passage, the bacteria can be observed within the cells of the intestinal epithelium. In such an oral infection model, the flies succumb to infection only after 6 days. We demonstrate that two complementary host defense mechanisms act together against such food-borne infection: an antimicrobial response in the intestine that is regulated by the imd pathway and phagocytosis by hemocytes of bacteria that have escaped into the hemolymph. Interestingly, bacteria present in the hemolymph elicit a systemic immune response only when phagocytosis is blocked. Our observations support a model wherein peptidoglycan fragments released during bacterial growth activate the imd pathway and do not back a proposed role for phagocytosis in the immune activation of the fat body. Thanks to the genetic tools available in both host and pathogen, the molecular dissection of the interactions between S. marcescens and Drosophila will provide a useful paradigm for deciphering intestinal pathogenesis.}, keywords = {Animal, Animals, Disease Models, Electron, ferrandon, fluorescence, Hemolymph, hoffmann, Host-Pathogen Interactions, Immunohistochemistry, Intestines, M3i, Microscopy, Reverse Transcriptase Polymerase Chain Reaction, Serratia Infections, Serratia marcescens, Transmission}, pubstate = {published}, tppubtype = {article} } Serratia marcescens is an entomopathogenic bacterium that opportunistically infects a wide range of hosts, including humans. In a model of septic injury, if directly introduced into the body cavity of Drosophila, this pathogen is insensitive to the host's systemic immune response and kills flies in a day. We find that S. marcescens resistance to the Drosophila immune deficiency (imd)-mediated humoral response requires the bacterial lipopolysaccharide O-antigen. If ingested by Drosophila, bacteria cross the gut and penetrate the body cavity. During this passage, the bacteria can be observed within the cells of the intestinal epithelium. In such an oral infection model, the flies succumb to infection only after 6 days. We demonstrate that two complementary host defense mechanisms act together against such food-borne infection: an antimicrobial response in the intestine that is regulated by the imd pathway and phagocytosis by hemocytes of bacteria that have escaped into the hemolymph. Interestingly, bacteria present in the hemolymph elicit a systemic immune response only when phagocytosis is blocked. Our observations support a model wherein peptidoglycan fragments released during bacterial growth activate the imd pathway and do not back a proposed role for phagocytosis in the immune activation of the fat body. Thanks to the genetic tools available in both host and pathogen, the molecular dissection of the interactions between S. marcescens and Drosophila will provide a useful paradigm for deciphering intestinal pathogenesis. |
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. |
Miturski, R; Postawski, K; Semczuk, A; Bogusiewicz, M; Baranowski, W; Jakowicki, J A; Keith, G Global DNA methylation in relation to hMLH1 and hMSH2 protein immunoreactivity in sporadic human endometrial carcinomas Article de journal Int J Mol Med, 11 (5), p. 569-74, 2003, (1107-3756 Journal Article). Résumé | BibTeX | Étiquettes: *DNA, Base, Carcinoma/genetics/*metabolism/pathology, DNA, Endometrial, Female, Gov't, Human, Immunohistochemistry, Methylation, Mismatch, Neoplasm, Neoplasms/genetics/*metabolism/pathology, Non-U.S., Pair, Proteins/*metabolism, Proto-Oncogene, Repair, Support @article{, title = {Global DNA methylation in relation to hMLH1 and hMSH2 protein immunoreactivity in sporadic human endometrial carcinomas}, author = { R. Miturski and K. Postawski and A. Semczuk and M. Bogusiewicz and W. Baranowski and J. A. Jakowicki and G. Keith}, year = {2003}, date = {2003-01-01}, journal = {Int J Mol Med}, volume = {11}, number = {5}, pages = {569-74}, abstract = {Overall DNA methylation status was studied in a group of 28 sporadic human endometrial carcinomas (ECs) using the [32P]-postlabeling technique. Moreover, expression of the DNA mismatch repair proteins (hMLH1 and hMSH2) was investigated in ECs using immunohistochemistry. Mean 5-methyldeoxycytosine (m5dC) content in the studied group was 3.48+/-0.37% (range, 2.89-4.12%). The mean m5dC scores were significantly different between early (3.35+/-0.33%) and advanced (3.66+/-0.36%) endometrial neoplasms (chi2-test; p=0.03). There was a markedly increased overall DNA methylation with the degree of histological differentiation and with the infiltration of the myometrium (p<0.05). Loss of hMLH1 and hMSH2 expression was reported in 7 (25%) and 5 (18%) tumors, respectively, but the immunoreactivity did not correlate with the known clinicopathological variables of cancer. In addition, no obvious correlation was found between global m5dC content and the lack of hMLH1 and hMSH2 protein expression in human uterine tumors (p=0.97 and p=0.19 for hMLH1 and hMSH2, respectively; Spearman's rank correlation test). Our results clearly show that alterations in global DNA methylation may influence tumor progression, but they are not directly associated with the inactivation of the mismatch-repair machinery in sporadic human ECs.}, note = {1107-3756 Journal Article}, keywords = {*DNA, Base, Carcinoma/genetics/*metabolism/pathology, DNA, Endometrial, Female, Gov't, Human, Immunohistochemistry, Methylation, Mismatch, Neoplasm, Neoplasms/genetics/*metabolism/pathology, Non-U.S., Pair, Proteins/*metabolism, Proto-Oncogene, Repair, Support}, pubstate = {published}, tppubtype = {article} } Overall DNA methylation status was studied in a group of 28 sporadic human endometrial carcinomas (ECs) using the [32P]-postlabeling technique. Moreover, expression of the DNA mismatch repair proteins (hMLH1 and hMSH2) was investigated in ECs using immunohistochemistry. Mean 5-methyldeoxycytosine (m5dC) content in the studied group was 3.48+/-0.37% (range, 2.89-4.12%). The mean m5dC scores were significantly different between early (3.35+/-0.33%) and advanced (3.66+/-0.36%) endometrial neoplasms (chi2-test; p=0.03). There was a markedly increased overall DNA methylation with the degree of histological differentiation and with the infiltration of the myometrium (p<0.05). Loss of hMLH1 and hMSH2 expression was reported in 7 (25%) and 5 (18%) tumors, respectively, but the immunoreactivity did not correlate with the known clinicopathological variables of cancer. In addition, no obvious correlation was found between global m5dC content and the lack of hMLH1 and hMSH2 protein expression in human uterine tumors (p=0.97 and p=0.19 for hMLH1 and hMSH2, respectively; Spearman's rank correlation test). Our results clearly show that alterations in global DNA methylation may influence tumor progression, but they are not directly associated with the inactivation of the mismatch-repair machinery in sporadic human ECs. |
2002 |
Munier, Anne-Isabelle; Doucet, Daniel; Perrodou, Emmanuel; Zachary, Daniel; Meister, Marie; Hoffmann, Jules A; Janeway, Charles A; Lagueux, Marie PVF2, a PDGF/VEGF-like growth factor, induces hemocyte proliferation in Drosophila larvae Article de journal EMBO Rep., 3 (12), p. 1195–1200, 2002, ISSN: 1469-221X. Résumé | Liens | BibTeX | Étiquettes: Animals, Antibodies, Blotting, Cell Differentiation, Hemocytes, hoffmann, Immunohistochemistry, Larva, ligands, M3i, Platelet-Derived Growth Factor, Receptors, Vascular Endothelial Growth Factor, Western @article{munier_pvf2_2002, title = {PVF2, a PDGF/VEGF-like growth factor, induces hemocyte proliferation in Drosophila larvae}, author = {Anne-Isabelle Munier and Daniel Doucet and Emmanuel Perrodou and Daniel Zachary and Marie Meister and Jules A Hoffmann and Charles A Janeway and Marie Lagueux}, doi = {10.1093/embo-reports/kvf242}, issn = {1469-221X}, year = {2002}, date = {2002-12-01}, journal = {EMBO Rep.}, volume = {3}, number = {12}, pages = {1195--1200}, abstract = {Blood cells play a crucial role in both morphogenetic and immunological processes in Drosophila, yet the factors regulating their proliferation remain largely unknown. In order to address this question, we raised antibodies against a tumorous blood cell line and identified an antigenic determinant that marks the surface of prohemocytes and also circulating plasmatocytes in larvae. This antigen was identified as a Drosophila homolog of the mammalian receptor for platelet-derived growth factor (PDGF)/vascular endothelial growth factor (VEGF). The Drosophila receptor controls cell proliferation in vitro. By overexpressing in vivo one of its putative ligands, PVF2, we induced a dramatic increase in circulating hemocytes. These results identify the PDGF/VEGF receptor homolog and one of its ligands as important players in Drosophila hematopoiesis.}, keywords = {Animals, Antibodies, Blotting, Cell Differentiation, Hemocytes, hoffmann, Immunohistochemistry, Larva, ligands, M3i, Platelet-Derived Growth Factor, Receptors, Vascular Endothelial Growth Factor, Western}, pubstate = {published}, tppubtype = {article} } Blood cells play a crucial role in both morphogenetic and immunological processes in Drosophila, yet the factors regulating their proliferation remain largely unknown. In order to address this question, we raised antibodies against a tumorous blood cell line and identified an antigenic determinant that marks the surface of prohemocytes and also circulating plasmatocytes in larvae. This antigen was identified as a Drosophila homolog of the mammalian receptor for platelet-derived growth factor (PDGF)/vascular endothelial growth factor (VEGF). The Drosophila receptor controls cell proliferation in vitro. By overexpressing in vivo one of its putative ligands, PVF2, we induced a dramatic increase in circulating hemocytes. These results identify the PDGF/VEGF receptor homolog and one of its ligands as important players in Drosophila hematopoiesis. |
Ligoxygakis, Petros; Bulet, Philippe; Reichhart, Jean-Marc Critical evaluation of the role of the Toll-like receptor 18-Wheeler in the host defense of Drosophila Article de journal EMBO Rep., 3 (7), p. 666–673, 2002, ISSN: 1469-221X. Résumé | Liens | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Cell Adhesion Molecules, Fat Body, Gene Expression Regulation, Genes, Immunohistochemistry, Immunologic, Insect, Insect Proteins, Larva, M3i, Mass, Matrix-Assisted Laser Desorption-Ionization, Membrane Proteins, Receptors, reichhart, Reporter, Spectrometry, Transgenes @article{ligoxygakis_critical_2002, title = {Critical evaluation of the role of the Toll-like receptor 18-Wheeler in the host defense of Drosophila}, author = {Petros Ligoxygakis and Philippe Bulet and Jean-Marc Reichhart}, doi = {10.1093/embo-reports/kvf130}, issn = {1469-221X}, year = {2002}, date = {2002-01-01}, journal = {EMBO Rep.}, volume = {3}, number = {7}, pages = {666--673}, abstract = {Essential aspects of innate immune responses to microbial infections appear to be conserved between insects and mammals. In particular, in both groups, transmembrane receptors of the Toll superfamily play a crucial role in activating immune defenses. The Drosophila Toll family member 18-Wheeler had been proposed to sense Gram-negative infection and direct selective expression of peptides active against Gram-negative bacteria. Here we re-examine the role of 18-Wheeler and show that in adults it is dispensable for immune responses. In larvae, 18wheeler is required for normal fat body development, and in mutant larvae induction of all antimicrobial peptide genes, and not only of those directed against Gram-negative bacteria, is compromised. 18-Wheeler does not qualify as a pattern recognition receptor of Gram-negative bacteria.}, keywords = {Animals, Anti-Bacterial Agents, Antimicrobial Cationic Peptides, Cell Adhesion Molecules, Fat Body, Gene Expression Regulation, Genes, Immunohistochemistry, Immunologic, Insect, Insect Proteins, Larva, M3i, Mass, Matrix-Assisted Laser Desorption-Ionization, Membrane Proteins, Receptors, reichhart, Reporter, Spectrometry, Transgenes}, pubstate = {published}, tppubtype = {article} } Essential aspects of innate immune responses to microbial infections appear to be conserved between insects and mammals. In particular, in both groups, transmembrane receptors of the Toll superfamily play a crucial role in activating immune defenses. The Drosophila Toll family member 18-Wheeler had been proposed to sense Gram-negative infection and direct selective expression of peptides active against Gram-negative bacteria. Here we re-examine the role of 18-Wheeler and show that in adults it is dispensable for immune responses. In larvae, 18wheeler is required for normal fat body development, and in mutant larvae induction of all antimicrobial peptide genes, and not only of those directed against Gram-negative bacteria, is compromised. 18-Wheeler does not qualify as a pattern recognition receptor of Gram-negative bacteria. |
2001 |
Lamberty, M; Zachary, Daniel; Lanot, R; Bordereau, C; Robert, A; Hoffmann, Jules A; Bulet, Philippe Insect immunity. Constitutive expression of a cysteine-rich antifungal and a linear antibacterial peptide in a termite insect. Article de journal J. Biol. Chem., 276 (6), p. 4085–4092, 2001, ISSN: 0021-9258. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Anti-Bacterial Agents, Antifungal Agents, Base Sequence, Chromatography, Cysteine, DNA Primers, High Pressure Liquid, hoffmann, Immunohistochemistry, Isoptera, M3i, Peptides, Protein Conformation, Recombinant Proteins, Sequence Homology @article{lamberty_insect_2001, title = {Insect immunity. Constitutive expression of a cysteine-rich antifungal and a linear antibacterial peptide in a termite insect.}, author = {M Lamberty and Daniel Zachary and R Lanot and C Bordereau and A Robert and Jules A Hoffmann and Philippe Bulet}, doi = {10.1074/jbc.M002998200}, issn = {0021-9258}, year = {2001}, date = {2001-02-01}, journal = {J. Biol. Chem.}, volume = {276}, number = {6}, pages = {4085--4092}, abstract = {Two novel antimicrobial peptides, which we propose to name termicin and spinigerin, have been isolated from the fungus-growing termite Pseudacanthotermes spiniger (heterometabole insect, Isoptera). Termicin is a 36-amino acid residue antifungal peptide, with six cysteines arranged in a disulfide array similar to that of insect defensins. In contrast to most insect defensins, termicin is C-terminally amidated. Spinigerin consists of 25 amino acids and is devoid of cysteines. It is active against bacteria and fungi. Termicin and spinigerin show no obvious sequence similarities with other peptides. Termicin is constitutively present in hemocyte granules and in salivary glands. The presence of termicin and spinigerin in unchallenged termites contrasts with observations in evolutionary recent insects or insects undergoing complete metamorphosis, in which antimicrobial peptides are induced in the fat body and released into the hemolymph after septic injury.}, keywords = {Amino Acid, Animals, Anti-Bacterial Agents, Antifungal Agents, Base Sequence, Chromatography, Cysteine, DNA Primers, High Pressure Liquid, hoffmann, Immunohistochemistry, Isoptera, M3i, Peptides, Protein Conformation, Recombinant Proteins, Sequence Homology}, pubstate = {published}, tppubtype = {article} } Two novel antimicrobial peptides, which we propose to name termicin and spinigerin, have been isolated from the fungus-growing termite Pseudacanthotermes spiniger (heterometabole insect, Isoptera). Termicin is a 36-amino acid residue antifungal peptide, with six cysteines arranged in a disulfide array similar to that of insect defensins. In contrast to most insect defensins, termicin is C-terminally amidated. Spinigerin consists of 25 amino acids and is devoid of cysteines. It is active against bacteria and fungi. Termicin and spinigerin show no obvious sequence similarities with other peptides. Termicin is constitutively present in hemocyte granules and in salivary glands. The presence of termicin and spinigerin in unchallenged termites contrasts with observations in evolutionary recent insects or insects undergoing complete metamorphosis, in which antimicrobial peptides are induced in the fat body and released into the hemolymph after septic injury. |
1995 |
Lemaitre, Bruno; Meister, Marie; Govind, S; Georgel, Philippe; Steward, R; Reichhart, Jean-Marc; Hoffmann, Jules A Functional analysis and regulation of nuclear import of dorsal during the immune response in Drosophila Article de journal EMBO J., 14 (3), p. 536–545, 1995, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Anti-Infective Agents, Antimicrobial Cationic Peptides, Biological Transport, Cell Nucleus, Cell Surface, DNA-Binding Proteins, Fat Body, Gene Expression Regulation, Genetic, hoffmann, Immunity, Immunohistochemistry, Insect Hormones, Insect Proteins, M3i, Melanins, Membrane Glycoproteins, Mutation, Neoplasms, Nuclear Proteins, Phosphoproteins, Receptors, reichhart, Signal Transduction, Toll-Like Receptors, Transcription, Transcription Factors @article{lemaitre_functional_1995, title = {Functional analysis and regulation of nuclear import of dorsal during the immune response in Drosophila}, author = {Bruno Lemaitre and Marie Meister and S Govind and Philippe Georgel and R Steward and Jean-Marc Reichhart and Jules A Hoffmann}, issn = {0261-4189}, year = {1995}, date = {1995-01-01}, journal = {EMBO J.}, volume = {14}, number = {3}, pages = {536--545}, abstract = {In addition to its function in embryonic development, the NF-kappa B/rel-related gene dorsal (dl) of Drosophila is expressed in larval and adult fat body where its RNA expression is enhanced upon injury. Injury also leads to a rapid nuclear translocation of dl from the cytoplasm in fat body cells. Here we present data which strongly suggest that the nuclear localization of dl during the immune response is controlled by the Toll signaling pathway, comprising gene products that participate in the intracellular part of the embryonic dorsoventral pathway. We also report that in mutants such as Toll or cactus, which exhibit melanotic tumor phenotypes, dl is constitutively nuclear. Together, these results point to a potential link between the Toll signaling pathway and melanotic tumor induction. Although dl has been shown previously to bind to kappa B-related motifs within the promoter of the antibacterial peptide coding gene diptericin, we find that injury-induced expression of diptericin can occur in the absence of dl. Furthermore, the melanotic tumor phenotype of Toll and cactus is not dl dependent. These data underline the complexity of the Drosophila immune response. Finally, we observed that like other rel proteins, dl can control the level of its own transcription.}, keywords = {Animals, Anti-Bacterial Agents, Anti-Infective Agents, Antimicrobial Cationic Peptides, Biological Transport, Cell Nucleus, Cell Surface, DNA-Binding Proteins, Fat Body, Gene Expression Regulation, Genetic, hoffmann, Immunity, Immunohistochemistry, Insect Hormones, Insect Proteins, M3i, Melanins, Membrane Glycoproteins, Mutation, Neoplasms, Nuclear Proteins, Phosphoproteins, Receptors, reichhart, Signal Transduction, Toll-Like Receptors, Transcription, Transcription Factors}, pubstate = {published}, tppubtype = {article} } In addition to its function in embryonic development, the NF-kappa B/rel-related gene dorsal (dl) of Drosophila is expressed in larval and adult fat body where its RNA expression is enhanced upon injury. Injury also leads to a rapid nuclear translocation of dl from the cytoplasm in fat body cells. Here we present data which strongly suggest that the nuclear localization of dl during the immune response is controlled by the Toll signaling pathway, comprising gene products that participate in the intracellular part of the embryonic dorsoventral pathway. We also report that in mutants such as Toll or cactus, which exhibit melanotic tumor phenotypes, dl is constitutively nuclear. Together, these results point to a potential link between the Toll signaling pathway and melanotic tumor induction. Although dl has been shown previously to bind to kappa B-related motifs within the promoter of the antibacterial peptide coding gene diptericin, we find that injury-induced expression of diptericin can occur in the absence of dl. Furthermore, the melanotic tumor phenotype of Toll and cactus is not dl dependent. These data underline the complexity of the Drosophila immune response. Finally, we observed that like other rel proteins, dl can control the level of its own transcription. |