First Author | Ramanathan S | Year | 2011 |
Journal | J Immunol | Volume | 186 |
Issue | 9 | Pages | 5131-41 |
PubMed ID | 21430227 | Mgi Jnum | J:172862 |
Mgi Id | MGI:5009153 | Doi | 10.4049/jimmunol.1001221 |
Citation | Ramanathan S, et al. (2011) Exposure to IL-15 and IL-21 enables autoreactive CD8 T cells to respond to weak antigens and cause disease in a mouse model of autoimmune diabetes. J Immunol 186(9):5131-41 |
abstractText | Autoreactive CD8(+) T lymphocytes play a key role in the pathogenesis of several autoimmune diseases. It is not yet well understood how autoreactive CD8(+) T cells, which express TCRs with low reactivity toward self-Ags, gain the ability to respond to autoantigens to cause disease. Previously, we have shown that prior stimulation of CD8(+) T cells with synergistic combinations of cytokines produced by the innate immune response, such as IL-21 and IL-15, induces Ag-independent proliferation. Such 'cytokine-primed' CD8 T cells displayed increased responsiveness to limiting quantities of the cognate Ag. In this paper, we report that prior stimulation with IL-15 and IL-21 also enables CD8(+) T cells to respond to weakly agonistic TCR ligands, resulting in proliferation, cytokine secretion, and cytolytic activity. Using a transgenic mouse model of autoimmune diabetes, we show that cytokine-primed autoreactive CD8(+) T cells induce disease following stimulation by weak TCR ligands, but their diabetogenic potential is dependent on continuous availability of IL-15 in vivo. These findings suggest that inflammatory cytokines could facilitate the triggering of autoreactive CD8(+) T cells by weak autoantigens, and this mechanism may have important implications for autoimmune diseases associated with microbial infections and chronic inflammation. |