Imagerie

@article{shahabuddin_plasmodium_1998,

title = {Plasmodium gallinaceum: differential killing of some mosquito stages of the parasite by insect defensin},

author = {M Shahabuddin and I Fields and Philippe Bulet and Jules A Hoffmann and L H Miller},

doi = {10.1006/expr.1998.4212},

issn = {0014-4894},

year  = {1998},

date = {1998-05-01},

journal = {Exp. Parasitol.},

volume = {89},

number = {1},

pages = {103--112},

abstract = {We examined several insect antimicrobial peptides to study their effect on Plasmodium gallinaceum zygotes, ookinetes, oocysts, and sporozoites. Only two insect defensins-Aeschna cyanea (dragon fly) and Phormia terranovae (flesh fly)-had a profound toxic effect on the oocysts in Aedes aegypti and on isolated sporozoites. The defensins affected the oocysts in a time-dependent manner. Injecting the peptide into the hemolymph 1 or 2 days after an infectious blood meal had no significant effect on prevalence of infection or relative oocyst density per mosquito. When injected 3 days after parasite ingestion, the relative oocyst density was significantly reduced. Injection on day 4 or later damaged the developing oocysts, although the oocysts density per mosquito was not significantly different when examined on day 8. The oocysts were swollen or had extensive internal vacuolization. The peptides had no detectable effect on the early stages of the parasite: the zygotes and ookinetes tested in vitro. Both the defensins were highly toxic to isolated sporozoites in vitro as indicated by disruption of the membrane permeability barrier, a change in morphology, and loss of motility. In contrast to the toxicity of cecropin and magainin for mosquitoes, defensin, at concentrations that kill parasites, is not toxic to mosquitoes, suggesting that defensin should be studied further as a potential molecule to block sporogonic development of Plasmodium.},

keywords = {Aedes, Animals, Anti-Infective Agents, Blood Proteins, Defensins, Diptera, hoffmann, Insect Vectors, insects, M3i, Plasmodium gallinaceum, Zygote},

pubstate = {published},

tppubtype = {article}

}

@article{bulet_insect_1995,

title = {Insect immunity. The inducible antibacterial peptide diptericin carries two O-glycans necessary for biological activity},

author = {Philippe Bulet and G Hegy and J Lambert and Alan van Dorsselaer and Jules A Hoffmann and Charles Hetru},

issn = {0006-2960},

year  = {1995},

date = {1995-06-01},

journal = {Biochemistry},

volume = {34},

number = {22},

pages = {7394--7400},

abstract = {A bacterial challenge of larvae of the dipteran insect Phormia terranovae induces the rapid synthesis of diptericin, an antibacterial polypeptide, previously characterized at the amino acid level and indirectly by cDNA cloning studies. This 82-residue polypeptide consists of an N-terminal proline-rich domain and a central and C-terminal glycine-rich domain. Using liquid chromatography coupled to electrospray ionization-mass spectrometry, we demonstrate here that this molecule is more complex than anticipated and carries two O-substitutions on threonine residues, one in the proline-rich domain (residue 10) and one in the glycine-rich domain (residue 54). These substitutions consist of identical trisaccharides: glucose--textgreatergalactose--textgreaterN-acetylgalactosamine--textgreater(threonine). Treatment of diptericin with O-glycosidase, which selectively removes the substitutions without altering the polypeptide proper, abolishes the antibacterial activity, indicating that this posttranslational modification is essential for biological activity of the polypeptide. We also show that diptericin is posttranslationally modified by a C-terminal amidation.},

keywords = {Animals, Anti-Bacterial Agents, Carbohydrate Sequence, Carbohydrates, Diptera, Escherichia coli, Glycopeptides, Hemolymph, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Mass Spectrometry, Plants, Trisaccharides},

pubstate = {published},

tppubtype = {article}

}

@article{cornet_refined_1995,

title = {Refined three-dimensional solution structure of insect defensin A},

author = {B Cornet and J M Bonmatin and Charles Hetru and Jules A Hoffmann and M Ptak and F Vovelle},

issn = {0969-2126},

year  = {1995},

date = {1995-05-01},

journal = {Structure},

volume = {3},

number = {5},

pages = {435--448},

abstract = {BACKGROUND: Insect defensin A is a basic 4 kDa protein secreted by Phormia terranovae larvae in response to bacterial challenges or injuries. Previous biological tests suggest that the bacterial cytoplasmic membrane is the target of defensin A. The structural study of this protein is the first step towards establishing a structure-activity relationship and forms the basis for understanding its antibiotic activity at the molecular level. RESULTS: We describe a refined model of the three-dimensional structure of defensin A derived from an extensive analysis of 786 inter-proton nuclear Overhauser effects. The backbone fold involves an N-terminal loop and an alpha-helical fragment followed by an antiparallel beta-structure. The helix and the beta-structure are connected by two of the three disulphide bridges present in defensin A, forming a so-called 'cysteine-stabilized alpha beta' (CS alpha beta) motif. The N-terminal loop, which is locally well defined, can occupy different positions with respect to the other moieties of the molecule. CONCLUSIONS: The CS alpha beta motif, which forms the core of the defensin A structure, appears to be a common organization for several families of small proteins with toxic properties. The distribution of amino acid side chains in the protein structure creates several hydrophobic or hydrophilic patches. This leads us to propose that the initial step in the action of positively charged defensin A molecules with cytoplasmic membranes may involve interactions with acidic phospholipids.},

keywords = {Amino Acid, Animals, Bacteriolysis, Chemistry, Defensins, Diptera, Gram-Positive Bacteria, hoffmann, Hydrogen Bonding, Insect Hormones, M3i, Magnetic Resonance Spectroscopy, Models, Molecular, Physical, Physicochemical Phenomena, Protein Conformation, Recombinant Proteins, Sequence Homology, Solutions, Structure-Activity Relationship},

pubstate = {published},

tppubtype = {article}

}

@article{lepage_determination_1991,

title = {Determination of disulfide bridges in natural and recombinant insect defensin A},

author = {P Lepage and F Bitsch and D Roecklin and E Keppi and Jean-Luc Dimarcq and Jean-Marc Reichhart and Jules A Hoffmann and C Roitsch and Van A Dorsselaer},

issn = {0014-2956},

year  = {1991},

date = {1991-01-01},

journal = {Eur. J. Biochem.},

volume = {196},

number = {3},

pages = {735--742},

abstract = {The primary-structure comparison of natural insect defensin A from Phormia terranovae and recombinant insect defensin A from Saccharomyces cerevisiae has been accomplished using a combination of Edman degradation and liquid secondary ion mass spectrometry. The natural and recombinant proteins have the same primary structure with identical disulfide-bond designations (formula; see text) as determined from the peptides obtained after thermolysin digestion. The combined use of Edman degradation and mass spectometry allowed the disulfide-bridge structure to be determined with a total of only 40 micrograms (9.9 nmol) natural peptide. Mass spectrometry provides a rapid means of disulfide-bridge verification, requiring not more than 20 micrograms recombinant insect defensin A, which is compatible with use in batch analysis.},

keywords = {Animals, Blood Proteins, Defensins, Diptera, Disulfides, Hemolymph, hoffmann, M3i, Mass Spectrometry, Recombinant Proteins, reichhart},

pubstate = {published},

tppubtype = {article}

}

@article{hoffmann_inducible_1990,

title = {The inducible antibacterial peptides of dipteran insects},

author = {Jules A Hoffmann and Danièle Hoffmann},

issn = {0923-2494},

year  = {1990},

date = {1990-12-01},

journal = {Res. Immunol.},

volume = {141},

number = {9},

pages = {910--918},

keywords = {Animals, Antimicrobial Cationic Peptides, Defensins, Diptera, Gene Expression Regulation, Genetic, hoffmann, Insect Hormones, Insect Proteins, M3i, Nucleic Acid, Proteins, Sequence Homology, Transcription},

pubstate = {published},

tppubtype = {article}

}

@article{dimarcq_insect_1990,

title = {Insect immunity: expression of the two major inducible antibacterial peptides, defensin and diptericin, in Phormia terranovae},

author = {Jean-Luc Dimarcq and Daniel Zachary and Jules A Hoffmann and Danièle Hoffmann and Jean-Marc Reichhart},

issn = {0261-4189},

year  = {1990},

date = {1990-08-01},

journal = {EMBO J.},

volume = {9},

number = {8},

pages = {2507--2515},

abstract = {Injections of low doses of bacteria into larvae of Phormia terranovae induce the appearance of potent bactericidal peptides in the blood, among which predominate the anti-Gram positive insect defensins and the anti-Gram negative diptericins. Insect defensins show significant homologies to mammalian (including human) microbicidal peptides present in polymorphonuclear leukocytes and macrophages. We report the molecular cloning of cDNAs and primer extension studies which indicate that insect defensin is produced as a prepro-peptide yielding mature defensin A (40 residues) after cleavage of a putative signal peptide (23 residues) and a prosequence (34 residues). Previous studies have established that diptericin (82 residues) is matured from a pre-peptide by cleavage of a putative signal peptide (19 residues) and C-terminal amidation. Using oligonucleotide probes complementary to the sequences of the mRNAs for defensin and diptericin, we show by in situ hybridization that both antibacterial peptides are concomitantly synthesized by the same cells: thrombocytoids, a specialized blood cell type, and adipocytes. Transcriptional studies based on hybridization of RNAs to cDNAs of defensin and diptericin indicate that the transcription of both genes is induced regardless of the nature of the stimulus (injection of Gram positive or Gram negative bacteria, lipopolysaccharides). Even a sterile injury applied to axenically raised larvae is efficient in inducing the transcription of both genes suggesting that the local disruption of the integument aspecifically initiates a signalling mechanism which the thrombocytoids and the adipocytes are able to interpret. The transcription of immune genes is relatively short lived and a second challenge yields a response similar to that of the first stimulus, indicating that the experimental insects do not keep a 'memory' of their first injection.},

keywords = {Animals, Anti-Bacterial Agents, Base Sequence, Blood Proteins, Cloning, Defensins, Diptera, Gene Expression, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Molecular, Nucleic Acid Hybridization, Oligonucleotide Probes, Protein Conformation, reichhart},

pubstate = {published},

tppubtype = {article}

}

@article{wicker_insect_1990,

title = {Insect immunity. Characterization of a Drosophila cDNA encoding a novel member of the diptericin family of immune peptides},

author = {C Wicker and Jean-Marc Reichhart and Danièle Hoffmann and D Hultmark and C Samakovlis and Jules A Hoffmann},

issn = {0021-9258},

year  = {1990},

date = {1990-01-01},

journal = {J. Biol. Chem.},

volume = {265},

number = {36},

pages = {22493--22498},

abstract = {Drosophila shows an immune response when challenged by injection of low doses of bacteria. To date, the molecules involved in this immune reaction have remained elusive, with the exception of cecropins (4-kDa antibacterial peptides initially isolated from the moth Hyalophora cecropia) for which three closely related genes have been characterized recently. We report the molecular cloning and sequencing of a cDNA from a library of immune Drosophila which encodes a novel member of the family of diptericins (9-kDa antibacterial peptides initially isolated from the fly Phormia terranovae). Transcripts for the Drosophila diptericin are detected 2 h after injection of bacteria. They are apparently derived from a single gene mapping at position 56 A on the right arm of the second chromosome. We discuss the existence of a distant relationship between the diptericins and two other groups of anti-bacterial insect proteins, the attacins, and the sarcotoxins II.},

keywords = {Animals, Anti-Bacterial Agents, Base Sequence, Cloning, Diptera, DNA, Escherichia coli, hoffmann, Insect Hormones, Insect Proteins, M3i, Molecular, Multigene Family, Nucleic Acid, Oligonucleotide Probes, reichhart, Sequence Homology},

pubstate = {published},

tppubtype = {article}

}

@article{reichhart_insect_1989,

title = {Insect immunity. Isolation of cDNA clones corresponding to diptericin, an inducible antibacterial peptide from Phormia terranovae (Diptera). Transcriptional profiles during immunization},

author = {Jean-Marc Reichhart and M Essrich and Jean-Luc Dimarcq and Danièle Hoffmann and Jules A Hoffmann and Marie Lagueux},

issn = {0014-2956},

year  = {1989},

date = {1989-01-01},

journal = {Eur. J. Biochem.},

volume = {182},

number = {2},

pages = {423--427},

abstract = {We have previously isolated and characterized a family of novel 8-kDa cationic antibacterial peptides synthesized by larvae of Phormia terranovae (Diptera) in response to various injuries. These molecules have been named diptericins. The peptide sequence of diptericin A was used to prepare oligonucleotides for screening cDNA libraries and we report in the present paper the isolation of several cDNA clones encoding diptericin. The analysis of the nucleotide sequences indicates that diptericin is synthesized as a prepeptide which is matured in two steps: (a) cleavage of a signal peptide and (b) amidation of the C-terminal residue. Interestingly, the 3' untranslated region of the mRNA contains a consensus sequence TTATTTAT which is also observed in the mRNA of another insect antibacterial peptide (attacin-related sarcotoxin IIA) and in mRNAs encoding proteins related to the inflammatory response in mammals. Our data illustrate that diptericins form a polymorphic family of immune peptides. The transcription of the diptericin genes is rapidly induced in the fat body after inoculation of bacteria, as evidenced by the transcriptional profile.},

keywords = {Animals, Anti-Bacterial Agents, Bacterial Proteins, Base Sequence, Blotting, Diptera, DNA, Endoribonucleases, Enterobacter, Enterobacteriaceae, Gene Expression Regulation, Genes, Genetic, hoffmann, Insect Hormones, Insect Proteins, M3i, messenger, MHC Class II, Northern, reichhart, Ribonuclease H, RNA, Transcription},

pubstate = {published},

tppubtype = {article}

}

@article{dimarcq_insect_1988,

title = {Insect immunity. Purification and characterization of a family of novel inducible antibacterial proteins from immunized larvae of the dipteran Phormia terranovae and complete amino-acid sequence of the predominant member, diptericin A},

author = {Jean-Luc Dimarcq and E Keppi and B Dunbar and J Lambert and Jean-Marc Reichhart and Danièle Hoffmann and S M Rankine and J E Fothergill and Jules A Hoffmann},

issn = {0014-2956},

year  = {1988},

date = {1988-01-01},

journal = {Eur. J. Biochem.},

volume = {171},

number = {1-2},

pages = {17--22},

abstract = {Injury or injection of live bacteria into third instar larvae of the dipteran insect Phormia terranovae results in the appearance in the haemolymph of at least five groups of heat-stable, more or less basic peptides with antibacterial activity against Escherichia coli. Three of these peptides have been purified. The amino acid sequence has been completely established for one of these and partially (first 40 residues from the N-terminus) for the two others. The sequences show marked homologies indicating that the three peptides belong to a common family. They are not related to other known antibacterial peptides from insects [lysozymes, cecropins (including sarcotoxin I) and attacins]. We propose the name of diptericins for this new family of antibiotic molecules.},

keywords = {Amino Acids, Animals, Anti-Bacterial Agents, Diptera, Escherichia coli, hoffmann, Insect Hormones, Insect Proteins, Isoelectric Point, Larva, M3i, reichhart},

pubstate = {published},

tppubtype = {article}

}

@article{zachary_endocrine_1980,

title = {Endocrine control of the metamorphosis of the larval muscles in Calliphora erythrocephala (Diptera): in vitro studies of the role of ecdysteroids},

author = {Daniel Zachary and Jules A Hoffmann},

issn = {0012-1606},

year  = {1980},

date = {1980-11-01},

journal = {Dev. Biol.},

volume = {80},

number = {1},

pages = {235--247},

keywords = {Animals, Biological, Diptera, Ecdysone, Ecdysterone, hoffmann, Larva, M3i, Metamorphosis, Muscles, Organ Culture Techniques},

pubstate = {published},

tppubtype = {article}

}

@article{brehelin_comparative_1977,

title = {Comparative study of hemocyte capsule formation in Locusta migratoria, Melolontha melolontha and Calliphora erythrocephala},

author = {M Brehelin and Daniel Zachary and Jules A Hoffmann},

issn = {0003-4150},

year  = {1977},

date = {1977-02-01},

journal = {Ann Parasitol Hum Comp},

volume = {52},

number = {1},

pages = {66--67},

keywords = {Animals, Beetles, Blood Cells, Cellular, Diptera, Grasshoppers, Hemocytes, hoffmann, Immunity, M3i},

pubstate = {published},

tppubtype = {article}

}

@article{zachary_role_1975,

title = {Role of the “thrombocytoids” in capsule formation in the dipteran Calliphora erythrocephala},

author = {Daniel Zachary and M Bréhelin and Jules A Hoffmann},

issn = {0302-766X},

year  = {1975},

date = {1975-10-01},

journal = {Cell Tissue Res.},

volume = {162},

number = {3},

pages = {343--348},

abstract = {Of the three hemocyte types present in the blood of Calliphora, only one participates in capsule formation around implanted cellophane. This hemocyte, the thrombocytoid, shows in the blood a tendency to dissociate into numerous small cytoplasmic fragments, comparable to the mammalian megakaryocyte. This tendency is dramatically increased during the process of encapsulation. Most of the intact thrombocytoids and the numerous fragments participating in capsule formation do not show any particular modifications in their cytoplasm during this process, which corresponds to a mere sequestration of the implant. Dense material, resulting from necrotic cell debris and hemolymph lipoproteins, is often observed between the cellophane and encapsulating thrombocytoids, which apparently participate in the resorption of this material.},

keywords = {Agglutination, Animals, Diptera, Foreign Bodies, Hemolymph, hoffmann, M3i, Phagocytosis},

pubstate = {published},

tppubtype = {article}

}

@article{zachary_haemocytes_1973,

title = {The haemocytes of Calliphora erythrocephala (Meig.) (Diptera)},

author = {Daniel Zachary and Jules A Hoffmann},

issn = {0340-0336},

year  = {1973},

date = {1973-07-01},

journal = {Z Zellforsch Mikrosk Anat},

volume = {141},

number = {1},

pages = {55--73},

keywords = {Animals, Cell Count, Cell Nucleus, Diptera, Electron, Endoplasmic Reticulum, Hemolymph, Hemostasis, hoffmann, Inclusion Bodies, Larva, Lipids, Lysosomes, M3i, Microscopy, mitochondria, Phase-Contrast, Pupa, Radiation Effects},

pubstate = {published},

tppubtype = {article}

}

@article{zachary_new_1972,

title = {A new type of blood cell (the thrombocytoid) in Calliphora erythrocephala},

author = {Daniel Zachary and Jules A Hoffmann and A Porte},

year  = {1972},

date = {1972-07-01},

journal = {C.R. Hebd. Seances Acad. Sci., Ser. D, Sci. Nat.},

volume = {275},

number = {3},

pages = {393--395},

keywords = {Animals, Blood Cells, Blood Platelets, Cell Membrane, Cell Nucleus, Cytoplasm, Diptera, Electron, Hemolymph, hoffmann, M3i, Microscopy, Phase-Contrast},

pubstate = {published},

tppubtype = {article}

}

@article{hoffmann_hemopoietic_1970,

title = {The hemopoietic organs of the two orthopterans Locusta migratoria and Gryllus bimaculatus},

author = {Jules A Hoffmann},

issn = {0340-0336},

year  = {1970},

date = {1970-01-01},

journal = {Z Zellforsch Mikrosk Anat},

volume = {106},

number = {3},

pages = {451--472},

keywords = {Animals, Cell Differentiation, Diptera, Electron, Hematopoiesis, Hematopoietic System, hoffmann, M3i, Microscopy, Species Specificity},

pubstate = {published},

tppubtype = {article}

}