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| Rosa, Rafael D.; Santini, Adrien; Fievet, Julie; Bulet, Philippe; Destoumieux-garzon, Delphine; Bachere, Evelyne. |
| Background: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Findings: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are... |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00050/16096/13576.pdf |
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| Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachere, Evelyne. |
| In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spectroscopy, and quantified its gene expression in vivo following bacterial challenge of oysters. Recombinant Cg-Def was active in vitro against Gram-positive bacteria but showed no or limited activities against Gram-negative bacteria and fungi. The activity of Cg-Def was... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Genomic library; Microbiology; Defensin; Oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2127.pdf |
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| Tetreau, Guillaume; Dhinaut, Julien; Galinier, Richard; Audant-lacour, Pascaline; Voisin, Sébastien N; Arafah, Karim; Chogne, Manon; Hilliou, Frédérique; Bordes, Anaïs; Sabarly, Camille; Chan, Philippe; Walet-balieu, Marie-laure; Vaudry, David; Duval, David; Bulet, Philippe; Coustau, Christine; Moret, Yannick; Gourbal, Benjamin. |
| In a number of species, individuals exposed to pathogens can mount an immune response and transmit this immunological experience to their offspring, thereby protecting them against persistent threats. Such vertical transfer of immunity, named trans-generational immune priming (TGIP), has been described in both vertebrates and invertebrates. Although increasingly studied during the last decade, the mechanisms underlying TGIP in invertebrates are still elusive, especially those protecting the earliest offspring life stage, i.e. the embryo developing in the egg. In the present study, we combined different proteomic and transcriptomic approaches to determine whether mothers transfer a “signal” (such as fragments of infecting bacteria), mRNA and/or... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00655/76684/77815.pdf |
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| Destoumieux, Delphine; Bulet, Philippe; Loew, Damarys; Van Dorsselaer, Alain; Rodriguez, Jenny; Bachere, Evelyne. |
| We report here the isolation of three members of a new family of antimicrobial peptides from the hemolymph of shrimps Penaeus vannamei in which immune response has not been experimentally induced. The three molecules display antimicrobial activity against fungi and bacteria with a predominant activity against Gram-positive bacteria. The complete sequences of these peptides were determined by a combination of enzymatic cleavages, Edman degradation, mass spectrometry, and cDNA cloning using a hemocyte cDNA library. The mature molecules (50 and 62 residues) are characterized by an NH2-terminal domain rich in proline residues and a COOH-terminal domain containing three intramolecular disulfide bridges. One of these molecules is post-translationally modified by... |
| Tipo: Text |
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| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00335/44649/57344.pdf |
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| Destoumieux, Delphine; Munoz, Marcello; Cosseau, Céline; Rodriguez, Jenny; Bulet, Philippe; Comps, Marie-annick; Bachere, Evelyne. |
| Penaeidins are members of a new family of antimicrobial peptides isolated from a crustacean, which present both Gram-positive antibacterial and antifungal activities. We have studied the localization of synthesis and storage of penaeidins in the shrimp Penaeus vannamei. The distribution of penaeidin transcripts and peptides in various tissues reveals that penaeidins are constitutively synthesized and stored in the shrimp haemocytes. It was shown by immunocytochemistry, at both optical and ultrastructural levels, that the peptides are localized in granulocyte cytoplasmic granules, The expression and localization of penaeidins were further analysed in shrimp subjected to microbial challenge. We found that (1) penaeidin mRNA levels decrease in circulating... |
| Tipo: Text |
Palavras-chave: Crustacean immunity; Penaeid shrimp; Haemocyte; Chitin binding; Antimicrobial peptide. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-412.pdf |
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| Gueguen, Yannick; Garnier, Julien; Robert, Lorenne; Lefranc, Marie-paule; Mougenot, Isabelle; De Lorgeril, Julien; Janech, Michael; Gross, Paul S.; Warr, Gregory W.; Cuthbertson, Brandon; Barracco, Margherita A.; Bulet, Philippe; Aumelas, André; Yang, Yinshan; Bo, Dong; Xiang, Jianhai; Tassanakajon, Anchalee; Piquemal, Piquemal; Bachere, Evelyne. |
| Antimicrobial peptides play a major role in innate immunity. The penaeidins, initially characterized from the shrimp Litopenaeus vannamei, are a family of antimicrobial peptides that appear to be expressed in all penaeid shrimps. As of recent, a large number of penaeid nucleotide sequences have been identified from a variety of penaeid shrimp species and these sequences currently reside in several databases under unique identifiers with no nomenclatural continuity. To facilitate research in this field and avoid potential confusion due to a diverse number of nomenclatural designations, we have made a systematic effort to collect, analyse, and classify all the penaeidin sequences available in every database. We have identified a common penaeidin signature... |
| Tipo: Text |
Palavras-chave: Nomenclature; Sequence database; Crustacea; Antimicrobial peptide; Penaeid shrimp; Penaeidin. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2332.pdf |
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| Loth, Karine; Vergnes, Agnes; Barreto, Cairé; Voisin, Sébastien N; Meudal, Hervé; Da Silva, Jennifer; Bressan, Albert; Belmadi, Nawal; Bachère, Evelyne; Aucagne, Vincent; Cazevielle, Chantal; Marchandin, Hélène; Rosa, Rafael Diego; Bulet, Philippe; Touqui, Lhousseine; Delmas, Agnès F.; Destoumieux-garzón, Delphine. |
| Big defensins, ancestors of β-defensins, are composed of a β-defensin-like C-terminal domain and a globular hydrophobic ancestral N-terminal domain. This unique structure is found in a limited number of phylogenetically distant species, including mollusks, ancestral chelicerates, and early-branching cephalochordates, mostly living in marine environments. One puzzling evolutionary issue concerns the advantage for these species of having maintained a hydrophobic domain lost during evolution toward β-defensins. Using native ligation chemistry, we produced the oyster Crassostrea gigas BigDef1 (Cg-BigDef1) and its separate domains. Cg-BigDef1 showed salt-stable and broad-range bactericidal activity, including against multidrug-resistant human clinical isolates... |
| Tipo: Text |
Palavras-chave: MRSA; Antimicrobial peptides; Antimicrobial resistance; Defensins; Fibrils; Innate immunity; Mechanisms of action; Nuclear magnetic resonance. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70057/68000.pdf |
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