Out-of-sequence signal 3 as a mechanism for virus-induced immune suppression of CD8 T cell responses.
PLoS Pathog
; 10(9): e1004357, 2014 Sep.
Article
en En
| MEDLINE
| ID: mdl-25255454
ABSTRACT
Virus infections are known to induce a transient state of immune suppression often associated with an inhibition of T cell proliferation in response to mitogen or cognate-antigen stimulation. Recently, virus-induced immune suppression has been linked to responses to type 1 interferon (IFN), a signal 3 cytokine that normally can augment the proliferation and differentiation of T cells exposed to antigen (signal 1) and co-stimulation (signal 2). However, pre-exposure of CD8 T cells to IFN-inducers such as viruses or poly(Iâ¶C) prior to antigen signaling is inhibitory, indicating that the timing of IFN exposure is of essence. We show here that CD8 T cells pretreated with poly(Iâ¶C) down-regulated the IFN receptor, up-regulated suppressor of cytokine signaling 1 (SOCS1), and were refractory to IFNß-induced signal transducers and activators of transcription (STAT) phosphorylation. When exposed to a viral infection, these CD8 T cells behaved more like 2-signal than 3-signal T cells, showing defects in short lived effector cell differentiation, reduced effector function, delayed cell division, and reduced levels of survival proteins. This suggests that IFN-pretreated CD8 T cells are unable to receive the positive effects that type 1 IFN provides as a signal 3 cytokine when delivered later in the signaling process. This desensitization mechanism may partially explain why vaccines function poorly in virus-infected individuals.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Interferón Tipo I
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Terapia de Inmunosupresión
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Linfocitos T CD8-positivos
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Proteínas Supresoras de la Señalización de Citocinas
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Coriomeningitis Linfocítica
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Virus de la Coriomeningitis Linfocítica
Límite:
Animals
Idioma:
En
Revista:
PLoS Pathog
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos