The virulence polysaccharide Vi released by Salmonella Typhi targets membrane prohibitin to inhibit T-cell activation.
J Infect Dis
; 210(1): 79-88, 2014 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-24470505
T cells are critical to immunity against pathogenic Salmonella including Salmonella Typhi which causes systemic infection, typhoid, in humans. The strategies that this pathogen employs to keep T-cell mediated immune responses in check during establishment of systemic infection are not completely understood. Here, we show that the virulence polysaccharide Vi, which distinguishes S. Typhi from localized gastroenteritis-producing nontyphoidal Salmonella serovars, is a potent inhibitor of T-cell activation. Vi released by S. Typhi interacts with the membrane prohibitin complex and inhibits IL-2 secretion from T cells stimulated through the T-cell receptor (TCR) but does not affect PMA-activated interleukin 2 (IL-2) secretion. Treatment with Vi suppresses early activation events including TCR down-regulation, actin polymerization, and phosphorylation of ERK. Coadministration of Vi with anti-CD3 Ab reduces secretion of IL-2 and interferon γ in mice. Our findings reveal a mechanism by which S. Typhi may target T-cell immunity during establishment of typhoid.
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Base de dados:
MEDLINE
Assunto principal:
Polissacarídeos Bacterianos
/
Proteínas Repressoras
/
Salmonella typhi
/
Ativação Linfocitária
/
Linfócitos T
/
Interleucina-2
/
Interações Hospedeiro-Patógeno
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article