Consulta: creatorFacets:"Rosa, Rafael Diego"
Registros recuperados: 7
Data/hora: 09/06/2024 02:16:40

The new insights into the oyster antimicrobial defense: Cellular, molecular and genetic view
Provedor de dados: 5
Autores: Bachere, Evelyne; Rosa, Rafael Diego; Schmitt, Paulina; Poirier, Aurore; Merou, Nicolas; Charriere, Guillaume; Destoumieux-garzon, Delphine.
Oysters are sessile filter feeders that live in close association with abundant and diverse communities of microorganisms that form the oyster microbiota. In such an association, cellular and molecular mechanisms have evolved to maintain oyster homeostasis upon stressful conditions including infection and changing environments. We give here cellular and molecular insights into the Crassostrea gigas antimicrobial defense system with focus on antimicrobial peptides and proteins (AMPs). This review highlights the central role of the hemocytes in the modulation and control of oyster antimicrobial response. As vehicles for AMPs and other antimicrobial effectors, including reactive oxygen species (ROS), and together with epithelia, hemocytes provide the oyster...
Tipo: Text
Palavras-chave: Mollusk; Immunity; Antimicrobial peptide; Hemocyte; Defensin.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00254/36552/35097.pdf

A hemocyte gene expression signature correlated with predictive capacity of oysters to survive Vibrio infections
Provedor de dados: 5
Autores: Rosa, Rafael Diego; De Lorgeril, Julien; Tailliez, Patrick; Bruno, Roman; Piquemal, David; Bachere, Evelyne.
Background: The complex balance between environmental and host factors is an important determinant of susceptibility to infection. Disturbances of this equilibrium may result in multifactorial diseases as illustrated by the summer mortality syndrome, a worldwide and complex phenomenon that affects the oysters, Crassostrea gigas. The summer mortality syndrome reveals a physiological intolerance making this oyster species susceptible to diseases. Exploration of genetic basis governing the oyster resistance or susceptibility to infections is thus a major goal for understanding field mortality events. In this context, we used high-throughput genomic approaches to identify genetic traits that may characterize inherent survival capacities in C. gigas. Results:...
Tipo: Text
Palavras-chave: Marine invertebrate; Mollusk bivalve; Mass mortality; Transcriptome-wide analysis; Digital gene expression; Microfluidic qPCR; Survival signature; Polymorphism; Gene copy number; Survival predictive biomarkers.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00095/20624/18262.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

Massive Gene Expansion and Sequence Diversification Is Associated with Diverse Tissue Distribution, Regulation and Antimicrobial Properties of Anti-Lipopolysaccharide Factors in Shrimp
Provedor de dados: 5
Autores: Matos, Gabriel Machado; Schmitt, Paulina; Barreto, Caire; Farias, Natanael Dantas; Toledo-silva, Guilherme; Guzman, Fanny; Destoumieux Garzon, Delphine; Perazzolo, Luciane Maria; Rosa, Rafael Diego.
Anti-lipopolysaccharide factors (ALFs) are antimicrobial peptides with a central β-hairpin structure able to bind to microbial components. Mining sequence databases for ALFs allowed us to show the remarkable diversity of ALF sequences in shrimp. We found at least seven members of the ALF family (Groups A to G), including two novel Groups (F and G), all of which are encoded by different loci with conserved gene organization. Phylogenetic analyses revealed that gene expansion and subsequent diversification of the ALF family occurred in crustaceans before shrimp speciation occurred. The transcriptional profile of ALFs was compared in terms of tissue distribution, response to two pathogens and during shrimp development in Litopenaeus vannamei, the most...
Tipo: Text
Palavras-chave: Host defense peptide; Antimicrobial peptide; Anti-LPS factor; Hostmicrobe relationship; Functional diversity; Invertebrate immunity; Crustacean; Antimicrobial activity.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00464/57523/59711.pdf

The Ancestral N-Terminal Domain of Big Defensins Drives Bacterially Triggered Assembly into Antimicrobial Nanonets
Provedor de dados: 5
Autores: 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

Litopenaeus vannamei stylicins are constitutively produced by hemocytes and intestinal cells and are differentially modulated upon infections
Provedor de dados: 5
Autores: Farias, Natanael Dantas; Falchetti, Marcelo; Matos, Gabriel Machado; Schmitt, Paulina; Barreto, Cairé; Argenta, Nicolas; Rolland, Jean-luc; Bachère, Evelyne; Perazzolo, Luciane Maria; Rosa, Rafael Diego.
Stylicins are anionic antimicrobial host defense peptides (AAMPs) composed of a proline-rich N-terminal region and a C-terminal portion containing 13 conserved cysteine residues. Here, we have increased our knowledge about these unexplored crustacean AAMPs by the characterization of novel stylicin members in the most cultivated penaeid shrimp, Litopenaeus vannamei. We showed that the L. vannamei stylicin family is composed of two members (Lvan-Stylicin1 and Lvan-Stylicin2) encoded by different loci which vary in gene copy number. Unlike the other three gene-encoded antimicrobial peptide families from penaeid shrimp, the expression of Lvan-Stylicins is not restricted to hemocytes. Indeed, they are also produced by the columnar epithelial cells lining the...
Tipo: Text
Palavras-chave: Crustacean; Penaeid shrimp; Invertebrate immunity; Antimicrobial peptide; Host defense peptide; Molecular diversity.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00466/57816/60102.pdf

Antimicrobial Peptides and Ectosymbiotic Relationships: Involvement of a Novel Type IIa Crustin in the Life Cycle of a Deep-Sea Vent Shrimp
Provedor de dados: 5
Autores: Le Bloa, Simon; Boidin-wichlacz, Céline; Cueff-gauchard, Valerie; Rosa, Rafael Diego; Cuvillier-hot, Virginie; Durand, Lucile; Methou, Pierre; Pradillon, Florence; Cambon-bonavita, Marie-anne; Tasiemski, Aurélie.
The symbiotic shrimp Rimicaris exoculata dominates the macrofauna inhabiting the active smokers of the deep-sea mid Atlantic ridge vent fields. We investigated the nature of the host mechanisms controlling the vital and highly specialized ectosymbiotic community confined into its cephalothoracic cavity. R. exoculata belongs to the Pleocyemata, crustacean brooding eggs, usually producing Type I crustins. Unexpectedly, a novel anti-Gram-positive type II crustin was molecularly identified in R. exoculata. Re-crustin is mainly produced by the appendages and the inner surfaces of the cephalothoracic cavity, embedding target epibionts. Symbiosis acquisition and regulating mechanisms are still poorly understood. Yet, symbiotic communities were identified at...
Tipo: Text
Palavras-chave: Extreme; Hydrothermal; Symbiosis; Host-microbe interaction; Invertebrate immunity; Crustacean.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75534/76413.pdf