When Toll-like receptor and T-cell receptor signals collide: a mechanism for enhanced CD8 T-cell effector function.
Blood
; 116(18): 3494-504, 2010 Nov 04.
Article
em En
| MEDLINE
| ID: mdl-20696947
ABSTRACT
Emerging reports reveal that activating Toll-like receptor-2 (TLR2)-MyD88 signals in CD8 T lymphocytes enhances cytokine production and cytotoxicity; however, the signaling pathway remains undefined. In the present study, we examined the physiologic significance and molecular mechanisms involved in this process. We found that TLR2 engagement on T-cell receptor transgenic CD8 OT-1 T cells increased T-bet transcription factor levels consequently, augmenting effector transcript and protein levels both in vivo and in vitro. In contrast, TLR2 agonist did not costimulate TLR2(-/-)OT-1 or MyD88(-/-)OT-1 T cells. Elevated T-bet levels in TLR2-MyD88-activated T cells was a consequence of increased biosynthesis resulting from the enhanced activation of the mammalian target of the rapamycin (mTOR) pathway. Inhibiting mTOR, Akt, or protein kinase C in T cells abolished the costimulatory effects of the TLR2 agonist. In vivo, activating TLR2-MyD88 signals in T cells increased effector-molecule levels and enhanced the clearance of Listeria monocytogenes-Ova. These results help define a signaling pathway linking the TLR-MyD88 and mTOR pathway in an Akt- and protein kinase C-dependent manner. These results highlight a critical role for MyD88 signaling in T-cell activation and cytotoxicity. Furthermore, these findings offer the opportunity for improving the efficacy of vaccines and T cell-based immunotherapies by targeting TLR-MyD88 signaling within T cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Antígenos de Linfócitos T
/
Linfócitos T CD8-Positivos
/
Receptores Toll-Like
Limite:
Animals
Idioma:
En
Revista:
Blood
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos