Consulta: creatorFacets:"Romestand, Bernard"
Registros recuperados: 12
Data/hora: 01/06/2024 11:55:46

Recherche et caractérisation d'immunoglobulines dans les oeufs du loup (Dicentrarchus labrax)
Provedor de dados: 5
Autores: Pepin, Jean-francois; Breuil, Gilles; Rigobert, P; Romestand, Bernard.
The occurrence of maternal immunity transfer in Sea bass (Dicentrarchus labrax) was investigated using ELISA and Western blot technics. In order to determine the possible presence of immunoglobulin (Ig), egg proteins obtained from fertilized eggs were analyzed. After several extraction protocol assays (precipitation, chromatography), monoclonal and polyclonal antibody probes specific to Sea bass Ig allowed to confirm the presence of an immunoglobulin-like protein in eggs with very low level. Biochemical characterization was carried out using SDS-PAGE. Results indicated that egg Ig had a molecular weight of 206 kDa. They were smaller than seric IgM (800 kDa). The heavy (H) and light (L) chains of the egg Ig and of the seric IgM had similar molecular weight,...
Tipo: Text
Palavras-chave: Immunoglobuline; Transfert immunité maternelle; ELISA; Œuf; Poisson; Immunoglobulin; Maternal immunity transfer; ELISA; Eggs; Fish.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00272/38275/36458.pdf

Differential distribution and defence involvement of antimicrobial peptides in mussel
Provedor de dados: 5
Autores: Mitta, Guillaume; Vandenbulcke, Franck; Noel, Thierry; Romestand, Bernard; Beauvillain, Jean Claude; Salzet, Michel; Roch, Philippe.
In previous papers, we characterised 3 types of 4-kDa, cysteine-rich, cationic antimicrobial peptides: MGDs (for Mytilus galloprovincialis defensins), mytilins and myticins, which are abundant in the mussel hemocytes. In the present work, me revealed a differential distribution of the cells expressing the different genes. In addition, using confocal and electron microscopy, we confirmed that defensins and mytilins were partially located in different sub-types of circulating hemocytes although the peptides can be located in the same cell, and even in the same granule. We also demonstrated that mytilins exert their microbicidal effect within the cells through the process of phagosome-mytilin granule fusion leading to the co-location of ingested bacteria and...
Tipo: Text
Palavras-chave: Innate immunity; Hemocyte; Mussel; Myticin; Mytilin; Defensin; Antimicrobial.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-413.pdf

Oyster hemocytes express a proline-rich peptide displaying synergistic antimicrobial activity with a defensin
Provedor de dados: 5
Autores: Gueguen, Yannick; Romestand, Bernard; Fievet, Julie; Schmitt, Paulina; Destoumieux Garzon, Delphine; Franck, Vandenbulcke; Philippe, Bulet; Bachere, Evelyne.
A cDNA sequence that encodes a 61-amino acid polypeptide precursor with homologies to proline-rich antimicrobial peptides (AMPs) was identified in the oyster Crassostrea gigas. After release of a hydrophobic signal peptide. the resulting 37-amino acid peptide, Cg-Prp, is composed of an acidic region and a cationic proline-rich region. To evaluate the biological properties of Cg-Prp, multiple proline-rich peptides corresponding to putative processing of the full-length Cg-Prp were synthesized. A limited antimicrobial activity was observed for two of them, which also showed strong synergistic antimicrobial activity with Cg-Def, a defensin from C gigas. To our knowledge, this is the first evidence of synergy between a defensin and another AMP in an...
Tipo: Text
Palavras-chave: Antimicrobial peptide; Mollusk; Synergy; Invertebrate; Innate immunity; Pacific oyster.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6232.pdf

Etude hematologique comparee des constantes erythrocytaires de quelques poissons marins et d'eaux douces.
Provedor de dados: 5
Autores: Romestand, Bernard; Halsband, Egon; Bragoni, Georges; Knezevic, Borivoj; Marjc, Drago; Prochnow, Friedrich.
A comparative haematological study of erythrocytic constants (erythrocytic numeration, haematocrit, haemoglobin, VGM, TGMH, CCMH) in some species of marine and freshwater fishes is envisaged. The comparison of these results shows that marine fishes have more circulant erythrocytes than the freshwater species as well as a weak VGM, CCMH values are rather constant (22%) for both categories. The occurrence of an adaptative mechanism allowing a better oxygenation of tissues is also discussed.
Tipo: Text
Palavras-chave: Yugoslavia MED; France Anguillidae Salmonidae Cyprinidae Percidae Sparidae Mugilidae Serranidae Gadidae Labridae Erythrocytes Hematology Fish physiology.
Ano: 1982
URL: http://archimer.ifremer.fr/doc/1982/publication-1857.pdf

Stylicins, a new family of antimicrobial peptides from the Pacific blue shrimp Litopenaeus stylirostris
Provedor de dados: 5
Autores: Rolland, Jean-luc; Abdelouahab, Mahdia; Dupont, J.; Lefevre, F.; Bachere, Evelyne; Romestand, Bernard.
The present study reports the characterization of Ls-Stylicin1, a novel antimicrobial peptide from the penaeid shrimp, Litopenoeus stylirostris. The predicted mature peptide of 82 residues is negatively charged (theoretical pl=5.0) and characterized by a proline-rich N-terminal region and a C-terminal region containing 13 cysteine residues. The recombinant Ls-Stylicin1 has been isolated in both monomeric and dimeric forms. Both display strong antifungal activity against Fusarium oxysporum (1.25 mu M &lt; MIC &lt;2.5 mu M), a pathogenic fungus of shrimp, but lower antimicrobial activity against Gram () bacteria, Vibrio sp. (40 mu M &lt; MIC &lt;80 mu M). However, rLs-Stylicin1 is able to agglutinate Vibrio pennaeicidae in vitro in agreement with its potent...
Tipo: Text
Palavras-chave: Ls-Stylicin 1; Peptide; Shrimp; Antifungal; Agglutination; Vibrio.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11387/8094.pdf

The major outer membrane protein OmpU of Vibrio splendidus contributes to host antimicrobial peptide resistance and is required for virulence in the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Duperthuy, Marylise; Binesse, Johan; Le Roux, Frederique; Romestand, Bernard; Caro, Audrey; Got, Patrice; Givaudan, Alain; Mazel, Didier; Bachere, Evelyne; Destoumieux Garzon, Delphine.
Vibrio splendidus, strain LGP32, is an oyster pathogen associated with the summer mortalities affecting the production of Crassostrea gigas oysters worldwide. Vibrio splendidus LGP32 was shown to resist to up to 10 mu M Cg-Def defensin and Cg-BPI bactericidal permeability increasing protein, two antimicrobial peptides/proteins (AMPs) involved in C. gigas immunity. The resistance to both oyster Cg-Def and Cg-BPI and standard AMPs (polymyxin B, protegrin, human BPI) was dependent on the ompU gene. Indeed, upon ompU inactivation, minimal bactericidal concentrations decreased by up to fourfold. AMP resistance was restored upon ectopic expression of ompU. The susceptibility of bacterial membranes to AMP-induced damages was independent of the ompU-mediated AMP...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11421/8044.pdf

Molecular characterization of two isoforms of defensin from hemocytes of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Gonzalez, Marcelo; Gueguen, Yannick; Desserre, Geraldine; De Lorgeril, Julien; Romestand, Bernard; Bachere, Evelyne.
Antimicrobial peptides (AMPs) are important components of the host innate immune response against microbial invasion. We previously characterized the first AMP from an oyster, a defensin, that was shown to be continuously expressed in the mantle of Crassostrea gigas. In this study, we report the cDNA cloning of two new isoforms of the defensin AMP family (Cg-defh1 and Cg-defh2) from the hemocytes of the oyster. The deduced amino acid sequences reveal two peptides of 73 amino acid residues with a mature portion consisting of 43 amino acid residues. Cy-Defh1 and CyDefh2 share 86% amino acid identity and belong to the "arthropod-molluscs defensin family". qRT-PCR analyses indicate that Cg-defh2 is continuously expressed in the hemocytes of C. gigas. In...
Tipo: Text
Palavras-chave: Defensin; Antimicrobial peptide; Hemocytes; Pacific oyster; Marine invertebrate; Mollusc bivalve.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2331.pdf

Evidence of a bactericidal permeability increasing protein in an invertebrate, the Crassostrea gigas Cg-BPI
Provedor de dados: 5
Autores: Gonzalez, Marcelo; Gueguen, Yannick; Destoumieux Garzon, Delphine; Romestand, Bernard; Fievet, Julie; Pugniere, M; Roquet, F; Escoubas, Jean-michel; Vandenbulcke, F; Levy, O; Saune, Laure; Bulet, P; Bachere, Evelyne.
A cDNA sequence with homologies to members of the LPS-binding protein and bactericidal/permeability-increasing protein (BPI) family was identified in the oyster Crassostrea gigas. The recombinant protein was found to bind LIPS, to display bactericidal activity against Escherichia coli, and to increase the permeability of the bacterial cytoplasmic membrane. This indicated that it is a BPI rather than an LPS-binding protein. By in situ hybridization, the expression of the C gigas BPI (Cg-bpi) was found to be induced in hemocytes after oyster bacterial challenge and to be constitutive in various epithelia of unchallenged oysters. Thus, Cg-bpi transcripts were detected in the epithelial cells of tissues/organs in contact with the external environment (mantle,...
Tipo: Text
Palavras-chave: Oyster innate immunity; Mollusk; Hemocyte; Epithelia; Antimicrobial.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3564.pdf

Evidence in oyster of a plasma extracellular superoxide dismutase which binds LPS
Provedor de dados: 5
Autores: Gonzalez, Marcelo; Romestand, Bernard; Fievet, Julie; Huvet, Arnaud; Lebart, M; Gueguen, Yannick; Bachere, Evelyne.
We have characterized in the oyster Crassostrea gigas an extracellular superoxide dismutase (Cg-EcSOD) which appears to bind lipopolysaccharides (LPS). The protein has been purified from the oyster plasma and identified as a Cu/ZnSOD according to its N-terminal sequencing and biological activity. Cg-EcSOD expression and synthesis are restricted to hemocytes as revealed by in situ hybridization and immunocytochemistry. Cg-EcSOD-expressing hemocytes were seen in blood circulation, in connective tissues, and closely associated to endothelium blood vessels. Cg-EcSOD presents in its amino acid sequence a LPS-binding motif found in the endotoxin receptor CD14 and we show that the protein displays an affinity to Escherichia coli bacteria and with LPS and Lipid A....
Tipo: Text
Palavras-chave: Beta integrin; Oxidative burst; Hemocyte; Crassostrea gigas; Invertebrate; Mollusc bivalve.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-3583.pdf

Functional Divergence in Shrimp Anti-Lipopolysaccharide Factors (ALFs): From Recognition of Cell Wall Components to Antimicrobial Activity
Provedor de dados: 5
Autores: Rosa, Rafael Diego; Vergnes, Agnes; De Lorgeril, Julien; Goncalves, Priscila; Perazzolo, Luciane Maria; Saune, Laure; Romestand, Bernard; Fievet, Julie; Gueguen, Yannick; Bachere, Evelyne; Destoumieux-garzon, Delphine.
Antilipopolysaccharide factors (ALFs) have been described as highly cationic polypeptides with a broad spectrum of potent antimicrobial activities. In addition, ALFs have been shown to recognize LPS, a major component of the Gram-negative bacteria cell wall, through conserved amino acid residues exposed in the four-stranded beta-sheet of their three dimensional structure. In penaeid shrimp, ALFs form a diverse family of antimicrobial peptides composed by three main variants, classified as ALF Groups A to C. Here, we identified a novel group of ALFs in shrimp (Group D ALFs), which corresponds to anionic polypeptides in which many residues of the LPS binding site are lacking. Both Group B (cationic) and Group D (anionic) shrimp ALFs were produced in a...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00160/27077/25236.pdf

Use of OmpU porins for attachment and invasion of Crassostrea gigas immune cells by the oyster pathogen Vibrio splendidus
Provedor de dados: 5
Autores: Duperthuy, Marylise; Schmitt, Paulina; Garzon, Edwin; Caro, Audrey; Rosa, Rafael D.; Le Roux, Frederique; Lautredou-audouy, Nicole; Got, Patrice; Romestand, Bernard; De Lorgeril, Julien; Kieffer-jaquinod, Sylvie; Bachere, Evelyne; Destoumieux-garzon, Delphine.
OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the human pathogen Vibrio cholera, require OmpU for host colonization and virulence. We have shown previously that OmpU is essential for virulence in the oyster pathogen Vibrio splendidus LGP32. Here, we showed that V. splendidus LGP32 invades the oyster immune cells, the hemocytes, through subversion of host-cell actin cytoskeleton. In this process, OmpU serves as an adhesin/invasin required for beta-integrin recognition and host cell invasion. Furthermore, the major protein of oyster plasma, the extracellular superoxide dismutase Cg-EcSOD, is used as an opsonin mediating the...
Tipo: Text
Palavras-chave: Host-pathogen interaction; Innate immunity; Invertebrate; Mollusk; Oxidative burst.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00031/14177/12166.pdf

Composition and antimicrobial activity of essential oils of Cinnamosma fragrans
Provedor de dados: 5
Autores: Randrianarivelo, Roger; Sarter, Sarnira; Odoux, Eric; Brat, Pierre; Lebrun, Marc; Romestand, Bernard; Menut, Chantal; Andrianoelisoa, Hanitriniaina Sahondra; Raherimandimby, Marson; Danthu, Pascal.
Essential oil samples of Cinnamosma fragrans from two regions in Madagascar, Tsaramandroso (38 samples) and Mariarano (30 samples), were analysed by GC/MS. Fifty-seven components were identified, accounting from 88.3% to 99.4% of the oils' composition. The major components were linalool (72.5 +/- 23.3%) in Tsaramandroso and 1,8-cineole (47.3 +/- 10.2%) in Mariarano. Samples B8 (95.8% linalool) from Tsaramandroso and B143 (71.6% 1,8-cineole) from Mariarano containing the highest proportions of the two main components identified, were selected to determine antimicrobial activities against 10 microbial strains. Bacillus subtilis and Staphylococcus aureus were the most sensitive strains to both oils. Minimum inhibitory concentration (MIC) values were lower for...
Tipo: Text
Palavras-chave: Madagascar; 1.8 Cineole; Linalool; Antimicrobial activity; Essential oil; Cinnamosma fragrans.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6242.pdf