First Author | Anfossi N | Year | 2004 |
Journal | J Immunol | Volume | 173 |
Issue | 6 | Pages | 3773-82 |
PubMed ID | 15356124 | Mgi Jnum | J:92767 |
Mgi Id | MGI:3054486 | Doi | 10.4049/jimmunol.173.6.3773 |
Citation | Anfossi N, et al. (2004) Expansion and function of CD8+ T cells expressing Ly49 inhibitory receptors specific for MHC class I molecules. J Immunol 173(6):3773-82 |
abstractText | MHC class I-specific Ly49 inhibitory receptors regulate NK cell activation, thereby preventing autologous damage to normal cells. Ly49 receptors are also expressed on a subset of CD8+ T cells whose origin and function remain unknown. We report here that, despite their phenotypic and cytolytic similarities, Ly49+CD8+ T cells and conventional Ly49-CD44high memory-phenotype CD8+ T cells present strikingly distinct features. First, under steady state conditions Ly49+CD8+ T cells are poor cytokine producers (TNF-alpha and IFN-gamma) upon TCR triggering. Second, Ly49+CD8+ T cells are not induced upon various settings of Ag immunization or microbial challenge. However, Ly49 can be induced on a fraction of self-specific CD8+ T cells if CD4+ T cells are present. Finally, the size of the Ly49+CD8+ T cell subset is selectively reduced in the absence of STAT1. These results indicate that Ly49 expression is associated with a differentiation program of cytolytic CD8+ T cells triggered upon chronic antigenic exposure. They further suggest that the size of the Ly49+CD8+ T cell subset marks a history of CD8+ T cell activation that might preferentially result from endogenous inducers of inflammation rather than from microbial infections. |