Publications
2014 |
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Articles de journaux |
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| 12. | Bonnay, François; Nguyen, Xuan-Hung; Cohen-Berros, Eva; Troxler, Laurent; Batsche, Eric; Camonis, Jacques; Takeuchi, Osamu; Reichhart, Jean-Marc; Matt, Nicolas Akirin specifies NF-κB selectivity of Drosophila innate immune response via chromatin remodeling Article de journal EMBO J., 33 (20), p. 2349–2362, 2014, ISSN: 1460-2075. Résumé | Liens | BibTeX | Étiquettes: bioinformatic, Cell Cycle Proteins, Chromatin Assembly and Disassembly, chromatin remodeling, DNA-Binding Proteins, Female, Genetic, Immunity, Innate, Innate immune response, Male, Mutation, NF-kappa B, NF‐κB, Promoter Regions, Proteomics, Trans-Activators, Transcription Factors, Transcriptional Activation, Two-Hybrid System Techniques @article{bonnay_akirin_2014, title = {Akirin specifies NF-κB selectivity of Drosophila innate immune response via chromatin remodeling}, author = { François Bonnay and Xuan-Hung Nguyen and Eva Cohen-Berros and Laurent Troxler and Eric Batsche and Jacques Camonis and Osamu Takeuchi and Jean-Marc Reichhart and Nicolas Matt}, doi = {10.15252/embj.201488456}, issn = {1460-2075}, year = {2014}, date = {2014-10-01}, journal = {EMBO J.}, volume = {33}, number = {20}, pages = {2349--2362}, abstract = {The network of NF-κB-dependent transcription that activates both pro- and anti-inflammatory genes in mammals is still unclear. As NF-κB factors are evolutionarily conserved, we used Drosophila to understand this network. The NF-κB transcription factor Relish activates effector gene expression following Gram-negative bacterial immune challenge. Here, we show, using a genome-wide approach, that the conserved nuclear protein Akirin is a NF-κB co-factor required for the activation of a subset of Relish-dependent genes correlating with the presence of H3K4ac epigenetic marks. A large-scale unbiased proteomic analysis revealed that Akirin orchestrates NF-κB transcriptional selectivity through the recruitment of the Osa-containing-SWI/SNF-like Brahma complex (BAP). Immune challenge in Drosophila shows that Akirin is required for the transcription of a subset of effector genes, but dispensable for the transcription of genes that are negative regulators of the innate immune response. Therefore, Akirins act as molecular selectors specifying the choice between subsets of NF-κB target genes. The discovery of this mechanism, conserved in mammals, paves the way for the establishment of more specific and less toxic anti-inflammatory drugs targeting pro-inflammatory genes.}, keywords = {bioinformatic, Cell Cycle Proteins, Chromatin Assembly and Disassembly, chromatin remodeling, DNA-Binding Proteins, Female, Genetic, Immunity, Innate, Innate immune response, Male, Mutation, NF-kappa B, NF‐κB, Promoter Regions, Proteomics, Trans-Activators, Transcription Factors, Transcriptional Activation, Two-Hybrid System Techniques}, pubstate = {published}, tppubtype = {article} } The network of NF-κB-dependent transcription that activates both pro- and anti-inflammatory genes in mammals is still unclear. As NF-κB factors are evolutionarily conserved, we used Drosophila to understand this network. The NF-κB transcription factor Relish activates effector gene expression following Gram-negative bacterial immune challenge. Here, we show, using a genome-wide approach, that the conserved nuclear protein Akirin is a NF-κB co-factor required for the activation of a subset of Relish-dependent genes correlating with the presence of H3K4ac epigenetic marks. A large-scale unbiased proteomic analysis revealed that Akirin orchestrates NF-κB transcriptional selectivity through the recruitment of the Osa-containing-SWI/SNF-like Brahma complex (BAP). Immune challenge in Drosophila shows that Akirin is required for the transcription of a subset of effector genes, but dispensable for the transcription of genes that are negative regulators of the innate immune response. Therefore, Akirins act as molecular selectors specifying the choice between subsets of NF-κB target genes. The discovery of this mechanism, conserved in mammals, paves the way for the establishment of more specific and less toxic anti-inflammatory drugs targeting pro-inflammatory genes. |
| 11. | Tartey, Sarang; Matsushita, Kazufumi ; Vandenbon, Alexis ; Ori, Daisuke ; Imamura, Tomoko ; Mino, Takashi ; Standley, Daron M; Hoffmann, Jules A; Reichhart, Jean-Marc ; Akira, Shizuo ; Takeuchi, Osamu Akirin2 is critical for inducing inflammatory genes by bridging IκB-ζ and the SWI/SNF complex Article de journal EMBO J., 33 (20), p. 2332–2348, 2014, ISSN: 1460-2075. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Cell Nucleus, Chromatin Assembly and Disassembly, chromatin remodeling, Chromosomal Proteins, cytokine, Cytokines, Female, Gene Expression Regulation, gene regulation, Genetic, Humans, Immunity, Innate, innate immunity, Knockout, Listeria monocytogenes, Macrophages, Male, Mice, Multiprotein Complexes, Non-Histone, Nuclear Proteins, Promoter Regions, Protein Binding, Repressor Proteins, Sequence Deletion, Signal Transducing, Transcriptional Activation @article{tartey_akirin2_2014, title = {Akirin2 is critical for inducing inflammatory genes by bridging IκB-ζ and the SWI/SNF complex}, author = { Sarang Tartey and Kazufumi Matsushita and Alexis Vandenbon and Daisuke Ori and Tomoko Imamura and Takashi Mino and Daron M. Standley and Jules A. Hoffmann and Jean-Marc Reichhart and Shizuo Akira and Osamu Takeuchi}, doi = {10.15252/embj.201488447}, issn = {1460-2075}, year = {2014}, date = {2014-10-01}, journal = {EMBO J.}, volume = {33}, number = {20}, pages = {2332--2348}, abstract = {Transcription of inflammatory genes in innate immune cells is coordinately regulated by transcription factors, including NF-κB, and chromatin modifiers. However, it remains unclear how microbial sensing initiates chromatin remodeling. Here, we show that Akirin2, an evolutionarily conserved nuclear protein, bridges NF-κB and the chromatin remodeling SWI/SNF complex by interacting with BRG1-Associated Factor 60 (BAF60) proteins as well as IκB-ζ, which forms a complex with the NF-κB p50 subunit. These interactions are essential for Toll-like receptor-, RIG-I-, and Listeria-mediated expression of proinflammatory genes including Il6 and Il12b in macrophages. Consistently, effective clearance of Listeria infection required Akirin2. Furthermore, Akirin2 and IκB-ζ recruitment to the Il6 promoter depend upon the presence of IκB-ζ and Akirin2, respectively, for regulation of chromatin remodeling. BAF60 proteins were also essential for the induction of Il6 in response to LPS stimulation. Collectively, the IκB-ζ-Akirin2-BAF60 complex physically links the NF-κB and SWI/SNF complexes in innate immune cell activation. By recruiting SWI/SNF chromatin remodellers to IκB-ζ, transcriptional coactivator for NF-κB, the conserved nuclear protein Akirin2 stimulates pro-inflammatory gene promoters in mouse macrophages during innate immune responses to viral or bacterial infection.}, keywords = {Adaptor Proteins, Cell Nucleus, Chromatin Assembly and Disassembly, chromatin remodeling, Chromosomal Proteins, cytokine, Cytokines, Female, Gene Expression Regulation, gene regulation, Genetic, Humans, Immunity, Innate, innate immunity, Knockout, Listeria monocytogenes, Macrophages, Male, Mice, Multiprotein Complexes, Non-Histone, Nuclear Proteins, Promoter Regions, Protein Binding, Repressor Proteins, Sequence Deletion, Signal Transducing, Transcriptional Activation}, pubstate = {published}, tppubtype = {article} } Transcription of inflammatory genes in innate immune cells is coordinately regulated by transcription factors, including NF-κB, and chromatin modifiers. However, it remains unclear how microbial sensing initiates chromatin remodeling. Here, we show that Akirin2, an evolutionarily conserved nuclear protein, bridges NF-κB and the chromatin remodeling SWI/SNF complex by interacting with BRG1-Associated Factor 60 (BAF60) proteins as well as IκB-ζ, which forms a complex with the NF-κB p50 subunit. These interactions are essential for Toll-like receptor-, RIG-I-, and Listeria-mediated expression of proinflammatory genes including Il6 and Il12b in macrophages. Consistently, effective clearance of Listeria infection required Akirin2. Furthermore, Akirin2 and IκB-ζ recruitment to the Il6 promoter depend upon the presence of IκB-ζ and Akirin2, respectively, for regulation of chromatin remodeling. BAF60 proteins were also essential for the induction of Il6 in response to LPS stimulation. Collectively, the IκB-ζ-Akirin2-BAF60 complex physically links the NF-κB and SWI/SNF complexes in innate immune cell activation. By recruiting SWI/SNF chromatin remodellers to IκB-ζ, transcriptional coactivator for NF-κB, the conserved nuclear protein Akirin2 stimulates pro-inflammatory gene promoters in mouse macrophages during innate immune responses to viral or bacterial infection. |
2005 |
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Articles de journaux |
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| 10. | 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: bioinformatic, DNA-Binding Proteins, Genetic, Genetically Modified, Insect Viruses, Janus Kinase 1, 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 = {bioinformatic, DNA-Binding Proteins, Genetic, Genetically Modified, Insect Viruses, Janus Kinase 1, 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. |
2003 |
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Articles de journaux |
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| 9. | 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, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, Insect Proteins, 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, Base Sequence, Cell Surface, Chimera, Cloning, Developmental, Female, Gene Expression Regulation, Genetic, Insect Proteins, 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. |
2000 |
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Articles de journaux |
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| 8. | 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: Biological, Cell Line, Cell Surface, Defensins, Genes, Genetic, Insect, Insect Proteins, Lipopolysaccharides, 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 = {Biological, Cell Line, Cell Surface, Defensins, Genes, Genetic, Insect, Insect Proteins, Lipopolysaccharides, 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. |
1998 |
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Articles de journaux |
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| 7. | Levashina, Elena A; Ohresser, S; Lemaitre, Bruno; Imler, Jean-Luc Two distinct pathways can control expression of the gene encoding the Drosophila antimicrobial peptide metchnikowin Article de journal Journal of Molecular Biology, 278 (3), p. 515–527, 1998, ISSN: 0022-2836. Résumé | Liens | BibTeX | Étiquettes: Anti-Infective Agents, Antimicrobial Cationic Peptides, Base Sequence, Cloning, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Glycopeptides, Insect, Insect Proteins, Larva, Molecular, Mutation, Peptides, Promoter Regions, Recombinant Fusion Proteins, Reporter, Restriction Mapping, Transcription @article{levashina_two_1998, title = {Two distinct pathways can control expression of the gene encoding the Drosophila antimicrobial peptide metchnikowin}, author = { Elena A. Levashina and S. Ohresser and Bruno Lemaitre and Jean-Luc Imler}, doi = {10.1006/jmbi.1998.1705}, issn = {0022-2836}, year = {1998}, date = {1998-01-01}, journal = {Journal of Molecular Biology}, volume = {278}, number = {3}, pages = {515--527}, abstract = {Metchnikowin is a recently discovered proline-rich peptide from Drosophila with antibacterial and antifungal properties. Like most other antimicrobial peptides from insects, its expression is immune-inducible. Here we present evidence that induction of metchnikowin gene expression can be mediated either by the TOLL pathway or by the imd gene product. We show that the gene remains inducible in Toll-deficient mutants, in which the antifungal response is blocked, as well as in imd mutants, which fail to mount an antibacterial response. However, in Toll-deficient;imd double mutants, metchnikowin gene expression can no longer be detected after immune challenge. Our results suggest that expression of this peptide with dual activity can be triggered by signals generated by either bacterial or fungal infection. Cloning of the metchnikowin gene revealed the presence in the 5' flanking region of several putative cis-regulatory motifs characterized in the promoters of insect immune genes: namely, Rel sites, GATA motifs, interferon consensus response elements and NF-IL6 response elements. Establishment of transgenic fly lines in which the GFP reporter gene was placed under the control of 1.5 kb of metchnikowin gene upstream sequences indicates that this fragment is able to confer full immune inducibility and tissue specificity of expression on the transgene.}, keywords = {Anti-Infective Agents, Antimicrobial Cationic Peptides, Base Sequence, Cloning, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Glycopeptides, Insect, Insect Proteins, Larva, Molecular, Mutation, Peptides, Promoter Regions, Recombinant Fusion Proteins, Reporter, Restriction Mapping, Transcription}, pubstate = {published}, tppubtype = {article} } Metchnikowin is a recently discovered proline-rich peptide from Drosophila with antibacterial and antifungal properties. Like most other antimicrobial peptides from insects, its expression is immune-inducible. Here we present evidence that induction of metchnikowin gene expression can be mediated either by the TOLL pathway or by the imd gene product. We show that the gene remains inducible in Toll-deficient mutants, in which the antifungal response is blocked, as well as in imd mutants, which fail to mount an antibacterial response. However, in Toll-deficient;imd double mutants, metchnikowin gene expression can no longer be detected after immune challenge. Our results suggest that expression of this peptide with dual activity can be triggered by signals generated by either bacterial or fungal infection. Cloning of the metchnikowin gene revealed the presence in the 5' flanking region of several putative cis-regulatory motifs characterized in the promoters of insect immune genes: namely, Rel sites, GATA motifs, interferon consensus response elements and NF-IL6 response elements. Establishment of transgenic fly lines in which the GFP reporter gene was placed under the control of 1.5 kb of metchnikowin gene upstream sequences indicates that this fragment is able to confer full immune inducibility and tissue specificity of expression on the transgene. |
1997 |
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Articles de journaux |
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| 6. | Meister, Marie; Lemaitre, Bruno; Hoffmann, Jules A Antimicrobial peptide defense in Drosophila Article de journal Bioessays, 19 (11), p. 1019–1026, 1997, ISSN: 0265-9247. Résumé | Liens | BibTeX | Étiquettes: Anti-Infective Agents, Gene Expression Regulation, Genetic, Insect Proteins, Models, Peptides, Promoter Regions, Signal Transduction @article{meister_antimicrobial_1997, title = {Antimicrobial peptide defense in Drosophila}, author = { Marie Meister and Bruno Lemaitre and Jules A. Hoffmann}, doi = {10.1002/bies.950191112}, issn = {0265-9247}, year = {1997}, date = {1997-11-01}, journal = {Bioessays}, volume = {19}, number = {11}, pages = {1019--1026}, abstract = {Drosophila responds to a septic injury by the rapid synthesis of antimicrobial peptides. These molecules are predominantly produced by the fat body, a functional equivalent of mammalian liver, and are secreted into the hemolymph where their concentrations can reach up to 100 microM. Six distinct antibacterial peptides (plus isoforms) and one antifungal peptide have been characterized in Drosophila and their genes cloned. The induction of the gene encoding the antifungal peptide relies on the spätzle/Toll/cactus gene cassette, which is involved in the control of dorsoventral patterning in the embryo, and shows interesting structural and functional similarities with cytokine-induced activation of NF-kappa B in mammalian cells. An additional pathway, dependent on the as yet unidentified imd (for immune-deficiency) gene, is required for the full induction of the antibacterial peptide genes. Mutants deficient for the Toll and imd pathways exhibit a severely reduced survival to fungal and bacterial infections, respectively. Recent data on the molecular mechanisms underlying recognition of non-self are also discussed in this review.}, keywords = {Anti-Infective Agents, Gene Expression Regulation, Genetic, Insect Proteins, Models, Peptides, Promoter Regions, Signal Transduction}, pubstate = {published}, tppubtype = {article} } Drosophila responds to a septic injury by the rapid synthesis of antimicrobial peptides. These molecules are predominantly produced by the fat body, a functional equivalent of mammalian liver, and are secreted into the hemolymph where their concentrations can reach up to 100 microM. Six distinct antibacterial peptides (plus isoforms) and one antifungal peptide have been characterized in Drosophila and their genes cloned. The induction of the gene encoding the antifungal peptide relies on the spätzle/Toll/cactus gene cassette, which is involved in the control of dorsoventral patterning in the embryo, and shows interesting structural and functional similarities with cytokine-induced activation of NF-kappa B in mammalian cells. An additional pathway, dependent on the as yet unidentified imd (for immune-deficiency) gene, is required for the full induction of the antibacterial peptide genes. Mutants deficient for the Toll and imd pathways exhibit a severely reduced survival to fungal and bacterial infections, respectively. Recent data on the molecular mechanisms underlying recognition of non-self are also discussed in this review. |
1995 |
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Articles de journaux |
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| 5. | Georgel, Philippe; Kappler, Christine ; Langley, E; Gross, I; Nicolas, E; Reichhart, Jean-Marc ; Hoffmann, Jules A Drosophila immunity. A sequence homologous to mammalian interferon consensus response element enhances the activity of the diptericin promoter Article de journal Nucleic Acids Res., 23 (7), p. 1140–1145, 1995, ISSN: 0305-1048. Résumé | BibTeX | Étiquettes: Base Sequence, CCAAT-Enhancer-Binding Proteins, DNA, DNA-Binding Proteins, Genes, Genetic, Immunity, Insect, Insect Hormones, Insect Proteins, Interferons, Lipopolysaccharides, NF-kappa B, Nuclear Proteins, Plasmids, Promoter Regions, Up-Regulation @article{georgel_drosophila_1995, title = {Drosophila immunity. A sequence homologous to mammalian interferon consensus response element enhances the activity of the diptericin promoter}, author = { Philippe Georgel and Christine Kappler and E. Langley and I. Gross and E. Nicolas and Jean-Marc Reichhart and Jules A. Hoffmann}, issn = {0305-1048}, year = {1995}, date = {1995-04-01}, journal = {Nucleic Acids Res.}, volume = {23}, number = {7}, pages = {1140--1145}, abstract = {Bacterial challenge of larvae or adults of Drosophila induces the rapid transcription of several genes encoding antibacterial peptides with a large spectrum of activity. One of these peptides, the 82-residue anti-gram negative diptericin, is encoded by a single intronless gene and we are investigating the control of expression of this gene. Previous studies using both transgenic experiments and footprint analysis have highlighted the role in the induction of this gene of a 30 nucleotide region which contains three partially overlapping motifs with sequence homology to mammalian NF-kappa B and NF-IL6 response elements and to the GAAANN sequence present in the interferon consensus response elements of some mammalian interferon-induced genes. We now show that the latter sequence binds in immune responsive tissues (fat body, blood cells) of Drosophila a approximately 45 kDa polypeptide which cross-reacts with a polyserum directed against mammalian interferon Regulatory Factor-I. Using a transfection assay of Drosophila tumorous blood cells, we show that the GAAANN sequence positively regulates the activity of the diptericin promoter. We propose that this motif cooperatively interacts with the other response elements in the regulation of the diptericin gene expression.}, keywords = {Base Sequence, CCAAT-Enhancer-Binding Proteins, DNA, DNA-Binding Proteins, Genes, Genetic, Immunity, Insect, Insect Hormones, Insect Proteins, Interferons, Lipopolysaccharides, NF-kappa B, Nuclear Proteins, Plasmids, Promoter Regions, Up-Regulation}, pubstate = {published}, tppubtype = {article} } Bacterial challenge of larvae or adults of Drosophila induces the rapid transcription of several genes encoding antibacterial peptides with a large spectrum of activity. One of these peptides, the 82-residue anti-gram negative diptericin, is encoded by a single intronless gene and we are investigating the control of expression of this gene. Previous studies using both transgenic experiments and footprint analysis have highlighted the role in the induction of this gene of a 30 nucleotide region which contains three partially overlapping motifs with sequence homology to mammalian NF-kappa B and NF-IL6 response elements and to the GAAANN sequence present in the interferon consensus response elements of some mammalian interferon-induced genes. We now show that the latter sequence binds in immune responsive tissues (fat body, blood cells) of Drosophila a approximately 45 kDa polypeptide which cross-reacts with a polyserum directed against mammalian interferon Regulatory Factor-I. Using a transfection assay of Drosophila tumorous blood cells, we show that the GAAANN sequence positively regulates the activity of the diptericin promoter. We propose that this motif cooperatively interacts with the other response elements in the regulation of the diptericin gene expression. |
1994 |
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Articles de journaux |
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| 4. | Meister, Marie; Braun, A; Kappler, Christine ; Reichhart, Jean-Marc ; Hoffmann, Jules A Insect immunity. A transgenic analysis in Drosophila defines several functional domains in the diptericin promoter Article de journal EMBO J., 13 (24), p. 5958–5966, 1994, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Anti-Infective Agents, Base Sequence, beta-Galactosidase, DNA Mutational Analysis, Female, Gene Expression Regulation, Genetic, Genetically Modified, Germ Cells, Insect Hormones, Insect Proteins, Male, Models, Nucleic Acid, Promoter Regions, Recombinant Fusion Proteins, Repetitive Sequences, Transformation @article{meister_insect_1994, title = {Insect immunity. A transgenic analysis in Drosophila defines several functional domains in the diptericin promoter}, author = { Marie Meister and A. Braun and Christine Kappler and Jean-Marc Reichhart and Jules A. Hoffmann}, issn = {0261-4189}, year = {1994}, date = {1994-12-01}, journal = {EMBO J.}, volume = {13}, number = {24}, pages = {5958--5966}, abstract = {Diptericins are antibacterial polypeptides which are strongly induced in the fat body and blood cells of dipteran insects in response to septic injury. The promoter of the single-copy, intronless diptericin gene of Drosophila contains several nucleotide sequences homologous to mammalian cis-regulatory motifs involved in the control of acute phase response genes. Extending our previous studies on the expression of the diptericin gene, we now report a quantitative analysis of the contribution of various putative regulatory elements to the bacterial inducibility of this gene, based on the generation of 60 transgenic fly lines carrying different elements fused to a reporter gene. Our data definitively identify two Kappa B-related motifs in the proximal promoter as the sites conferring inducibility and tissue-specific expression to the diptericin gene. These motifs alone, however, mediate only minimal levels of expression. Additional proximal regulatory elements are necessary to attain some 20% of the full response and we suspect a role for sequences homologous to mammalian IL6 response elements and interferon-gamma responsive sites in this up-regulation. The transgenic experiments also reveal the existence of a distal regulatory element located upstream of -0.6 kb which increases the level of expression by a factor of five.}, keywords = {Anti-Infective Agents, Base Sequence, beta-Galactosidase, DNA Mutational Analysis, Female, Gene Expression Regulation, Genetic, Genetically Modified, Germ Cells, Insect Hormones, Insect Proteins, Male, Models, Nucleic Acid, Promoter Regions, Recombinant Fusion Proteins, Repetitive Sequences, Transformation}, pubstate = {published}, tppubtype = {article} } Diptericins are antibacterial polypeptides which are strongly induced in the fat body and blood cells of dipteran insects in response to septic injury. The promoter of the single-copy, intronless diptericin gene of Drosophila contains several nucleotide sequences homologous to mammalian cis-regulatory motifs involved in the control of acute phase response genes. Extending our previous studies on the expression of the diptericin gene, we now report a quantitative analysis of the contribution of various putative regulatory elements to the bacterial inducibility of this gene, based on the generation of 60 transgenic fly lines carrying different elements fused to a reporter gene. Our data definitively identify two Kappa B-related motifs in the proximal promoter as the sites conferring inducibility and tissue-specific expression to the diptericin gene. These motifs alone, however, mediate only minimal levels of expression. Additional proximal regulatory elements are necessary to attain some 20% of the full response and we suspect a role for sequences homologous to mammalian IL6 response elements and interferon-gamma responsive sites in this up-regulation. The transgenic experiments also reveal the existence of a distal regulatory element located upstream of -0.6 kb which increases the level of expression by a factor of five. |
1993 |
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Articles de journaux |
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| 3. | Georgel, Philippe; Meister, Marie ; Kappler, Christine ; Lemaitre, Bruno ; Reichhart, Jean-Marc ; Hoffmann, Jules A Insect immunity: the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute-phase response elements Article de journal Biochem. Biophys. Res. Commun., 197 (2), p. 508–517, 1993, ISSN: 0006-291X. Résumé | Liens | BibTeX | Étiquettes: Acute-Phase Proteins, Anti-Infective Agents, Base Sequence, Cell Line, Deoxyribonuclease I, DNA-Binding Proteins, Genetic, Insect Hormones, Insect Proteins, Larva, Mammals, NF-kappa B, Nucleic Acid, Oligonucleotide Probes, Polymerase Chain Reaction, Promoter Regions, Regulatory Sequences @article{georgel_insect_1993, title = {Insect immunity: the diptericin promoter contains multiple functional regulatory sequences homologous to mammalian acute-phase response elements}, author = { Philippe Georgel and Marie Meister and Christine Kappler and Bruno Lemaitre and Jean-Marc Reichhart and Jules A. Hoffmann}, doi = {10.1006/bbrc.1993.2508}, issn = {0006-291X}, year = {1993}, date = {1993-12-01}, journal = {Biochem. Biophys. Res. Commun.}, volume = {197}, number = {2}, pages = {508--517}, abstract = {We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila blood cell line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements.}, keywords = {Acute-Phase Proteins, Anti-Infective Agents, Base Sequence, Cell Line, Deoxyribonuclease I, DNA-Binding Proteins, Genetic, Insect Hormones, Insect Proteins, Larva, Mammals, NF-kappa B, Nucleic Acid, Oligonucleotide Probes, Polymerase Chain Reaction, Promoter Regions, Regulatory Sequences}, pubstate = {published}, tppubtype = {article} } We are using the diptericin gene as a model system to study the control of expression of the genes encoding antibacterial peptides during the Drosophila immune reaction. In order to investigate the putative regulatory regions in the diptericin promoter, we performed DNaseI footprinting experiments combined with gel-shift assays in two inducible systems: the larval fat body and a tumorous Drosophila blood cell line. Our results confirm the importance of kappa B-like elements previously described in the immune response of insects and reveal for the first time the involvement of other regions containing sequences homologous to mammalian acute-phase response elements. |
| 2. | Kappler, Christine; Meister, Marie ; Lagueux, Marie ; Gateff, E; Hoffmann, Jules A; Reichhart, Jean-Marc Insect immunity. Two 17 bp repeats nesting a kappa B-related sequence confer inducibility to the diptericin gene and bind a polypeptide in bacteria-challenged Drosophila Article de journal EMBO J., 12 (4), p. 1561–1568, 1993, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Anti-Bacterial Agents, Base Sequence, Cloning, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Insect, Insect Hormones, Insect Proteins, Lipopolysaccharides, Messenger, Molecular, NF-kappa B, Nucleic Acid, Oligodeoxyribonucleotides, Promoter Regions, Regulatory Sequences, RNA, Transfection @article{kappler_insect_1993, title = {Insect immunity. Two 17 bp repeats nesting a kappa B-related sequence confer inducibility to the diptericin gene and bind a polypeptide in bacteria-challenged Drosophila}, author = { Christine Kappler and Marie Meister and Marie Lagueux and E. Gateff and Jules A. Hoffmann and Jean-Marc Reichhart}, issn = {0261-4189}, year = {1993}, date = {1993-04-01}, journal = {EMBO J.}, volume = {12}, number = {4}, pages = {1561--1568}, abstract = {The Drosophila diptericin gene codes for a 9 kDa antibacterial peptide and is rapidly and transiently expressed in larvae and adults after bacterial challenge. It is also induced in a tumorous Drosophila blood cell line by the addition of lipopolysaccharide (LPS). The promoter of this gene contains two 17 bp repeats located closely upstream of the TATA-box and harbouring a decameric kappa B-related sequence. This study reports that the replacement of the two 17 bp repeats by random sequences abolishes bacteria inducibility in transgenic fly lines. In transfected tumorous blood cells, the replacement of both or either of the 17 bp motifs reduces dramatically LPS inducibility, whereas multiple copies significantly increase the level of transcriptional activation by LPS challenge. A specific DNA-protein binding activity is evidenced in cytoplasmic and nuclear extracts of induced blood cells and fat body. It is absent in controls. It is proposed that induction of the diptericin gene mediated by the two 17 bp repeats occurs via a mechanism similar to that of mammalian NF-kappa B.}, keywords = {Anti-Bacterial Agents, Base Sequence, Cloning, Gene Expression Regulation, Genes, Genetic, Genetically Modified, Insect, Insect Hormones, Insect Proteins, Lipopolysaccharides, Messenger, Molecular, NF-kappa B, Nucleic Acid, Oligodeoxyribonucleotides, Promoter Regions, Regulatory Sequences, RNA, Transfection}, pubstate = {published}, tppubtype = {article} } The Drosophila diptericin gene codes for a 9 kDa antibacterial peptide and is rapidly and transiently expressed in larvae and adults after bacterial challenge. It is also induced in a tumorous Drosophila blood cell line by the addition of lipopolysaccharide (LPS). The promoter of this gene contains two 17 bp repeats located closely upstream of the TATA-box and harbouring a decameric kappa B-related sequence. This study reports that the replacement of the two 17 bp repeats by random sequences abolishes bacteria inducibility in transgenic fly lines. In transfected tumorous blood cells, the replacement of both or either of the 17 bp motifs reduces dramatically LPS inducibility, whereas multiple copies significantly increase the level of transcriptional activation by LPS challenge. A specific DNA-protein binding activity is evidenced in cytoplasmic and nuclear extracts of induced blood cells and fat body. It is absent in controls. It is proposed that induction of the diptericin gene mediated by the two 17 bp repeats occurs via a mechanism similar to that of mammalian NF-kappa B. |
1992 |
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Articles de journaux |
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| 1. | Reichhart, Jean-Marc; Meister, Marie ; Dimarcq, Jean-Luc ; Zachary, Daniel ; Hoffmann, Danièle ; Ruiz, C; Richards, G; Hoffmann, Jules A Insect immunity: developmental and inducible activity of the Drosophila diptericin promoter Article de journal EMBO J., 11 (4), p. 1469–1477, 1992, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Acute-Phase Proteins, Adipose Tissue, Base Sequence, beta-Galactosidase, Embryo, Gene Expression Regulation, Genetic, Insect Hormones, Insect Proteins, Mammals, Nonmammalian, Oligodeoxyribonucleotides, Promoter Regions, Recombinant Fusion Proteins, Restriction Mapping @article{reichhart_insect_1992, title = {Insect immunity: developmental and inducible activity of the Drosophila diptericin promoter}, author = { Jean-Marc Reichhart and Marie Meister and Jean-Luc Dimarcq and Daniel Zachary and Danièle Hoffmann and C. Ruiz and G. Richards and Jules A. Hoffmann}, issn = {0261-4189}, year = {1992}, date = {1992-01-01}, journal = {EMBO J.}, volume = {11}, number = {4}, pages = {1469--1477}, abstract = {Diptericins are 9 kDa inducible antibacterial peptides initially isolated from immune haemolymph of Phormia (Diptera). Following the isolation of a Drosophila cDNA encoding a diptericin homologue, we have now cloned a genomic fragment containing the Drosophila diptericin gene. To dissect the regulation of this gene, we have transformed flies with a fusion gene in which the reporter beta-galactosidase gene is under the control of 2.2 kb upstream sequences of the diptericin gene. We show that such a fusion gene is inducible by injection of live bacteria or complete Freund's adjuvant and respects the tissue specific expression pattern of the resident diptericin gene. Our analysis reveals at least four distinct phases in the regulation of this gene: young larvae, late third instar larvae, pupae and adults. This complexity may be related to the presence in the upstream sequences of multiple copies of response elements previously characterized in genes encoding acute phase response proteins in mammals (e.g. NK-kappa B, NF-kappa B related, NF-IL6 response elements).}, keywords = {Acute-Phase Proteins, Adipose Tissue, Base Sequence, beta-Galactosidase, Embryo, Gene Expression Regulation, Genetic, Insect Hormones, Insect Proteins, Mammals, Nonmammalian, Oligodeoxyribonucleotides, Promoter Regions, Recombinant Fusion Proteins, Restriction Mapping}, pubstate = {published}, tppubtype = {article} } Diptericins are 9 kDa inducible antibacterial peptides initially isolated from immune haemolymph of Phormia (Diptera). Following the isolation of a Drosophila cDNA encoding a diptericin homologue, we have now cloned a genomic fragment containing the Drosophila diptericin gene. To dissect the regulation of this gene, we have transformed flies with a fusion gene in which the reporter beta-galactosidase gene is under the control of 2.2 kb upstream sequences of the diptericin gene. We show that such a fusion gene is inducible by injection of live bacteria or complete Freund's adjuvant and respects the tissue specific expression pattern of the resident diptericin gene. Our analysis reveals at least four distinct phases in the regulation of this gene: young larvae, late third instar larvae, pupae and adults. This complexity may be related to the presence in the upstream sequences of multiple copies of response elements previously characterized in genes encoding acute phase response proteins in mammals (e.g. NK-kappa B, NF-kappa B related, NF-IL6 response elements). |
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