Consulta: creatorFacets:"Rosa, Rafael D."
Registros recuperados: 7
Data/hora: 06/06/2024 11:54:19

Whole Transcriptome Profiling of Successful Immune Response to Vibrio Infections in the Oyster Crassostrea gigas by Digital Gene Expression Analysis
Provedor de dados: 5
Autores: De Lorgeril, Julien; Zenagui, Reda; Rosa, Rafael D.; Piquemal, David; Bachere, Evelyne.
The cultivated Pacific oyster Crassostrea gigas has suffered for decades large scale summer mortality phenomenon resulting from the interaction between the environment parameters, the oyster physiological and/or genetic status and the presence of pathogenic microorganisms including Vibrio species. To obtain a general picture of the molecular mechanisms implicated in C. gigas immune responsiveness to circumvent Vibrio infections, we have developed the first deep sequencing study of the transcriptome of hemocytes, the immunocompetent cells. Using Digital Gene Expression (DGE), we generated a transcript catalog of up-regulated genes from oysters surviving infection with virulent Vibrio strains (Vibrio splendidus LGP32 and V. aestuarianus LPi 02/41) compared...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00043/15377/12735.pdf

High polymorphism in big defensin gene expression reveals presence-absence gene variability (PAV) in the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Rosa, Rafael D.; Alonso, Pascal; Santini, Adrien; Vergnes, Agnes; Bachere, Evelyne.
We report here the first evidence in an invertebrate, the oyster Crassostrea gigas, of a phenomenon of Presence-Absence Variation (PAV) affecting immune-related genes. We previously evidenced an extraordinary interindividual variability in the basal mRNA abundances of oyster immune genes including those coding for a family of antimicrobial peptides, the big defensins (Cg-BigDef). Cg-BigDef is a diverse family composed of three members: Cg-BigDef1 to -3. Here, we show that besides a high polymorphism in Cg-BigDef mRNA expression, not all individual oysters express simultaneously the three Cg-BigDefs. Moreover, in numerous individuals, no expression of Cg-BigDefs could be detected. Further investigation at the genomic level revealed that in individuals in...
Tipo: Text
Palavras-chave: Mollusk bivalve; Antimicrobial peptide; Polymorphism; Gene copy number variation; High-throughput microfluidic RT-qPCR; Vibrio infection.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00239/35009/33545.pdf

An intimate link between antimicrobial peptide sequence diversity and binding to essential components of bacterial membranes
Provedor de dados: 5
Autores: Schmitt, Paulina; Rosa, Rafael D.; Destoumieux-garzon, Delphine.
Antimicrobial peptides and proteins (AMPs) are widespread in the living kingdom. They are key effectors of defense reactions and mediators of competitions between organisms. They are often cationic and amphiphilic, which favors their interactions with the anionic membranes of microorganisms. Several AMP families do not directly alter membrane integrity but rather target conserved components of the bacterial membranes in a process that provides them with potent and specific antimicrobial activities. Thus, lipopolysaccharides (LPS), lipoteichoic acids (LTA) or the peptidoglycan precursor Lipid II are targeted by a broad series of AMPs. Studying the functional diversity of immune effectors tells us about the essential residues involved in AMP mechanism of...
Tipo: Text
Palavras-chave: Functional diversity; Defensin; Anti-lipopolysaccharide factor; Mechanism of action; Resistance.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00286/39710/38165.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

Exploring the Impact of the Biofloc Rearing System and an Oral WSSV Challenge on the Intestinal Bacteriome of Litopenaeus vannamei
Provedor de dados: 5
Autores: Pilotto, Mariana R.; Goncalves, Andre N. A.; Vieira, Felipe N.; Seifert, Walter Q.; Bachere, Evelyne; Rosa, Rafael D.; Perazzolo, Luciane M.
We provide a global overview of the intestinal bacteriome of Litopenaeus vannamei in two rearing systems and after an oral challenge by the White spot syndrome virus (WSSV). By using a high-throughput 16S rRNA gene sequencing technology, we identified and compared the composition and abundance of bacterial communities from the midgut of shrimp reared in the super-intensive biofloc technology (BFT) and clear seawater system (CWS). The predominant bacterial group belonged to the phylum Proteobacteria, followed by the phyla Bacteroidetes, Actinobacteria, and Firmicutes. Within Proteobacteria, the family Vibrionaceae, which includes opportunistic shrimp pathogens, was more abundant in CWS than in BFT-reared shrimp. Whereas the families Rhodobacteraceae and...
Tipo: Text
Palavras-chave: Biofloc technology (BFT); Penaeid shrimp; Gut microbiota; White spot syndrome virus; 16S rRNA gene sequencing.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56546/58256.pdf

Antimicrobial histones and DNA traps in invertebrate immunity: evidences in Crassostrea gigas.
Provedor de dados: 5
Autores: Poirier, Aurore C.; Schmitt, Paulina; Rosa, Rafael D.; Vanhove, Audrey S.; Kieffer-jaquinod, Sylvie; Rubio, Tristan P.; Charriere, Guillaume M.; Destoumieux-garzon, Delphine.
Although antimicrobial histones have been isolated from multiple metazoan species, their role in host defense has long remained unanswered. We found here that the hemocytes of the oyster Crassostrea gigas release antimicrobial H1-like and H5-like histones in response to tissue damage and infection. These antimicrobial histones were shown to be associated with extracellular DNA networks released by hemocytes, the circulating immune cells of invertebrates, in response to immune challenge. The hemocyte-released DNA was found to surround and entangle vibrios. This defense mechanism is reminiscent of the neutrophil extracellular traps (ETs) recently described in vertebrates. Importantly, oyster ETs were evidenced in vivo in hemocyte-infiltrated interstitial...
Tipo: Text
Palavras-chave: Antimicrobial Peptide (AMP); DNA; Innate Immunity; Invertebrate; Reactive Oxygen Species (ROS); NET; Mollusk.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00217/32866/31784.pdf

Big Defensins, a Diverse Family of Antimicrobial Peptides That Follows Different Patterns of Expression in Hemocytes of the Oyster Crassostrea gigas
Provedor de dados: 5
Autores: 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...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00050/16096/13576.pdf