Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster
Vibrio strains belonging to the Splendidus Clade have been repeatedly found in juvenile diseased oysters affected by summer mortalities. V. tasmaniensis LGP32 is an intracellular pathogen of oyster hemocytes which has been reported to alter the oxidative burst and inhibit phagosome maturation. We sh...
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fttriple:oai:gotriple.eu:10670/1.xrnfx3 2023-05-15T15:58:32+02:00 Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster Survie intracellulaire, effets cytopathiques et virulence de Vibrio tasmaniensis LGP32, pathogène de l’huître Crassostrea gigas Vanhove, Audrey Montpellier 1 Destoumieux-Garzón, Delphine 2014-12-11 http://www.theses.fr/2014MON13518 fr fre 10670/1.xrnfx3 http://www.theses.fr/2014MON13518 other Theses.fr Interaction hôte-Pathogène Vibrio Processus infectieux Mécanismes d’échappement Immunité innée Host-Pathogen interaction Infectious process Escape Innate immunity envir socio Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2014 fttriple 2023-01-22T18:02:36Z Vibrio strains belonging to the Splendidus Clade have been repeatedly found in juvenile diseased oysters affected by summer mortalities. V. tasmaniensis LGP32 is an intracellular pathogen of oyster hemocytes which has been reported to alter the oxidative burst and inhibit phagosome maturation. We show here that LGP32 behaves as an intravacuolar pathogen that survives within large cytoplasmic vacuoles. LGP32 induces cytotoxic effects such as membrane disruptions and cytoplasmic disorders. Cytotoxicity was shown to be entirely dependent on LGP32 entry into hemocytes. Moreover, LGP32 releases outer membrane vesicles (OMVs) inside the phagosome. LGP32 OMVs were found to be protective against host defenses and to serve as vehicles for the delivery of LGP32 virulence factors to oyster immune cells. Indeed, OMVs conferred a high resistance to antimicrobial peptides. They also displayed a high content in hydrolases (25 % of total proteome) among which a serine protease, named Vsp for vesicular serine protease, was found to be specifically secreted through OMVs. Vsp was shown to participate in the virulence phenotype of LGP32 in oyster experimental infections but did not degrade AMPs entrapped in OMVs. By developing a transcriptomic approach, we identified a series of Vibrio antioxidant and copper efflux genes whose expression is strongly induced within oyster hemocytes. Construction of isogenic deletion mutants showed that resistance to reactive oxygen species and copper efflux are two important functions required for LGP32 intracellular survival, cytotoxic effects and virulence. Their high conservation among vibrios suggests they could contribute to intracellular survival of other Vibrio species. Des souches de Vibrio appartenant au clade Splendidus sont retrouvées de manière récurrente lors des mortalités estivales d'huîtres juvéniles. La souche V. tasmaniensis LGP32 est un pathogène intracellulaire facultatif des hémocytes d'huître, dont elle altère les fonctions de défense. Nous montrons ici que LGP32 se comporte ... Thesis Crassostrea gigas Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
Interaction hôte-Pathogène Vibrio Processus infectieux Mécanismes d’échappement Immunité innée Host-Pathogen interaction Infectious process Escape Innate immunity envir socio |
spellingShingle |
Interaction hôte-Pathogène Vibrio Processus infectieux Mécanismes d’échappement Immunité innée Host-Pathogen interaction Infectious process Escape Innate immunity envir socio Vanhove, Audrey Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster |
topic_facet |
Interaction hôte-Pathogène Vibrio Processus infectieux Mécanismes d’échappement Immunité innée Host-Pathogen interaction Infectious process Escape Innate immunity envir socio |
description |
Vibrio strains belonging to the Splendidus Clade have been repeatedly found in juvenile diseased oysters affected by summer mortalities. V. tasmaniensis LGP32 is an intracellular pathogen of oyster hemocytes which has been reported to alter the oxidative burst and inhibit phagosome maturation. We show here that LGP32 behaves as an intravacuolar pathogen that survives within large cytoplasmic vacuoles. LGP32 induces cytotoxic effects such as membrane disruptions and cytoplasmic disorders. Cytotoxicity was shown to be entirely dependent on LGP32 entry into hemocytes. Moreover, LGP32 releases outer membrane vesicles (OMVs) inside the phagosome. LGP32 OMVs were found to be protective against host defenses and to serve as vehicles for the delivery of LGP32 virulence factors to oyster immune cells. Indeed, OMVs conferred a high resistance to antimicrobial peptides. They also displayed a high content in hydrolases (25 % of total proteome) among which a serine protease, named Vsp for vesicular serine protease, was found to be specifically secreted through OMVs. Vsp was shown to participate in the virulence phenotype of LGP32 in oyster experimental infections but did not degrade AMPs entrapped in OMVs. By developing a transcriptomic approach, we identified a series of Vibrio antioxidant and copper efflux genes whose expression is strongly induced within oyster hemocytes. Construction of isogenic deletion mutants showed that resistance to reactive oxygen species and copper efflux are two important functions required for LGP32 intracellular survival, cytotoxic effects and virulence. Their high conservation among vibrios suggests they could contribute to intracellular survival of other Vibrio species. Des souches de Vibrio appartenant au clade Splendidus sont retrouvées de manière récurrente lors des mortalités estivales d'huîtres juvéniles. La souche V. tasmaniensis LGP32 est un pathogène intracellulaire facultatif des hémocytes d'huître, dont elle altère les fonctions de défense. Nous montrons ici que LGP32 se comporte ... |
author2 |
Montpellier 1 Destoumieux-Garzón, Delphine |
format |
Thesis |
author |
Vanhove, Audrey |
author_facet |
Vanhove, Audrey |
author_sort |
Vanhove, Audrey |
title |
Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster |
title_short |
Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster |
title_full |
Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster |
title_fullStr |
Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster |
title_full_unstemmed |
Intracellular survival, cytopathic effects and virulence of Vibrio tasmaniensis, a pathogen of Crassostrea gigas oyster |
title_sort |
intracellular survival, cytopathic effects and virulence of vibrio tasmaniensis, a pathogen of crassostrea gigas oyster |
publishDate |
2014 |
url |
http://www.theses.fr/2014MON13518 |
genre |
Crassostrea gigas |
genre_facet |
Crassostrea gigas |
op_source |
Theses.fr |
op_relation |
10670/1.xrnfx3 http://www.theses.fr/2014MON13518 |
op_rights |
other |
_version_ |
1766394289309351936 |