Influenza infection results in local expansion of memory CD8(+) T cells with antigen non-specific phenotype and function.
Clin Exp Immunol
; 175(1): 79-91, 2014 Jan.
Article
en En
| MEDLINE
| ID: mdl-23937663
ABSTRACT
Primary viral infections induce activation of CD8(+) T cells responsible for effective resistance. We sought to characterize the nature of the CD8(+) T cell expansion observed after primary viral infection with influenza. Infection of naive mice with different strains of influenza resulted in the rapid expansion of memory CD8(+) T cells exhibiting a unique bystander phenotype with significant up-regulation of natural killer group 2D (NKG2D), but not CD25, on the CD44(high) CD8(+) T cells, suggesting an antigen non-specific phenotype. We further confirmed the non-specificity of this phenotype on ovalbumin-specific (OT-I) CD8(+) T cells, which are not specific to influenza. These non-specific CD8(+) T cells also displayed increased lytic capabilities and were observed primarily in the lung. Thus, influenza infection was shown to induce a rapid, antigen non-specific memory T cell expansion which is restricted to the specific site of inflammation. In contrast, CD8(+) T cells of a similar phenotype could be observed in other organs following administration of systemic agonistic anti-CD40 and interleukin-2 immunotherapy, demonstrating that bystander expansion in multiple sites is possible depending on whether the nature of activation is either acute or systemic. Finally, intranasal blockade of NKG2D resulted in a significant increase in viral replication early during the course of infection, suggesting that NKG2D is a critical mediator of anti-influenza responses prior to the initiation of adaptive immunity. These results characterize further the local bystander expansion of tissue-resident, memory CD8(+) T cells which, due to their early induction, may play an important NKG2D-mediated, antigen non-specific role during the early stages of viral infection.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Virus de la Influenza A
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Replicación Viral
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Infecciones por Orthomyxoviridae
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Linfocitos T CD8-positivos
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Efecto Espectador
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Memoria Inmunológica
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Pulmón
Límite:
Animals
Idioma:
En
Revista:
Clin Exp Immunol
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos