M3i

@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}
}

@article{petrillo_cytoplasmic_2013,
title = {Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2},
author = {Jessica E Petrillo and Arno P Venter and James R Short and Radhika Gopal and Safia Deddouche and Olivier Lamiable and Jean-Luc Imler and Anette Schneemann},
doi = {10.1128/JVI.02362-13},
issn = {1098-5514},
year = {2013},
date = {2013-12-01},
journal = {Journal of Virology},
volume = {87},
number = {24},
pages = {13409--13421},
abstract = {Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle.},
keywords = {Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins},
pubstate = {published},
tppubtype = {article}
}

@article{kobayashi_shigella_2013,
title = {The Shigella OspC3 effector inhibits caspase-4, antagonizes inflammatory cell death, and promotes epithelial infection},
author = {Taira Kobayashi and Michinaga Ogawa and Takahito Sanada and Hitomi Mimuro and Minsoo Kim and Hiroshi Ashida and Reiko Akakura and Mitsutaka Yoshida and Magdalena Kawalec and Jean-Marc Reichhart and Tsunehiro Mizushima and Chihiro Sasakawa},
doi = {10.1016/j.chom.2013.04.012},
issn = {1934-6069},
year = {2013},
date = {2013-05-01},
journal = {Cell Host Microbe},
volume = {13},
number = {5},
pages = {570--583},
abstract = {Caspase-mediated inflammatory cell death acts as an intrinsic defense mechanism against infection. Bacterial pathogens deploy countermeasures against inflammatory cell death, but the mechanisms by which they do this remain largely unclear. In a screen for Shigella flexneri effectors that regulate cell death during infection, we discovered that Shigella infection induced acute inflammatory, caspase-4-dependent epithelial cell death, which is counteracted by the bacterial OspC3 effector. OspC3 interacts with the caspase-4-p19 subunit and inhibits its activation by preventing caspase-4-p19 and caspase-4-p10 heterodimerization by depositing the conserved OspC3 X1-Y-X₂-D-X₃ motif at the putative catalytic pocket of caspase-4. Infection of guinea pigs with a Shigella ospC3-deficient mutant resulted in enhanced inflammatory cell death and associated symptoms, correlating with decreased bacterial burdens. Salmonella Typhimurium and enteropathogenic Escherichia coli infection also induced caspase-4-dependent epithelial death. These findings highlight the importance of caspase-4-dependent innate immune responses and demonstrate that Shigella delivers a caspase-4-specific inhibitor to delay epithelial cell death and promote infection.},
keywords = {Animal, Animals, Bacillary, Bacterial, Bacterial Proteins, Caspases, Cell Death, Cell Line, Disease Models, DNA, Dysentery, Enzyme Inhibitors, Epithelial Cells, Escherichia coli, Gene Knockout Techniques, Guinea Pigs, Host-Pathogen Interactions, Humans, Initiator, M3i, Protein Binding, Protein Interaction Mapping, reichhart, Salmonella typhimurium, Sequence Analysis, Shigella flexneri, Virulence Factors},
pubstate = {published},
tppubtype = {article}
}

@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}
}

@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}
}

@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}
}

@article{tauszig_toll-related_2000,
title = {Toll-related receptors and the control of antimicrobial peptide expression in Drosophila},
author = {Servane Tauszig and Emmanuelle Jouanguy and Jules A Hoffmann and Jean-Luc Imler},
doi = {10.1073/pnas.180130797},
issn = {0027-8424},
year = {2000},
date = {2000-09-01},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {97},
number = {19},
pages = {10520--10525},
abstract = {Insects defend themselves against infectious microorganisms by synthesizing potent antimicrobial peptides. Drosophila has appeared in recent years as a favorable model to study this innate host defense. A genetic analysis of the regulation of the antifungal peptide drosomycin has demonstrated a key role for the transmembrane receptor Toll, which prompted the search for mammalian homologs. Two of these, Toll-like receptor (TLR)2 and TLR4, recently were shown to play a critical role in innate immunity against bacteria. Here we describe six additional Toll-related genes (Toll-3 to Toll-8) in Drosophila in addition to 18-wheeler. Two of these genes, Toll-3 and Toll-4, are expressed at a low level. Toll-6, -7, and -8, on the other hand, are expressed at high levels during embryogenesis and molting, suggesting that, like Toll and 18w, they perform developmental functions. Finally, Toll-5 is expressed only in larvae and adults. By using chimeric constructs, we have tested the capacity of the signaling Toll/IL-1R homology domains of these receptors to activate antimicrobial peptide promoters and found that only Toll and Toll-5 can activate the drosomycin promoter in transfected cells, thus demonstrating specificity at the level of the Toll/IL-1R homology domain. In contrast, none of these constructs activated antibacterial peptide promoters, suggesting that Toll-related receptors are not involved in the regulation of antibacterial peptide expression. This result was independently confirmed by the demonstration that a dominant-negative version of the kinase Pelle can block induction of drosomycin by the cytokine Spaetzle, but does not affect induction of the antibacterial peptide attacin by lipopolysaccharide.},
keywords = {Amino Acid, Animals, Anti-Bacterial Agents, Blotting, Cell Line, Cell Surface, hoffmann, imler, M3i, Membrane Glycoproteins, Multigene Family, Northern, Peptides, Receptors, Reverse Transcriptase Polymerase Chain Reaction, Sequence Homology, Toll-Like Receptor 2, Toll-Like Receptor 4, Toll-Like Receptor 5, Toll-Like Receptors},
pubstate = {published},
tppubtype = {article}
}

@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}
}

@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, Animals, Anti-Infective Agents, Base Sequence, Cell Line, Deoxyribonuclease I, DNA-Binding Proteins, Genetic, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Mammals, NF-kappa B, Nucleic Acid, Oligonucleotide Probes, Polymerase Chain Reaction, Promoter Regions, Regulatory Sequences, reichhart},
pubstate = {published},
tppubtype = {article}
}