Cd8(+) T Cells Sabotage Their Own Memory Potential Through Ifn-Gamma-Dependent Modification Of The Il-12/Il-15 Receptor Alpha Axis On Dendritic Cells

CD8(+) T cell responses have been shown to be regulated by dendritic cells (DCs) and CD4(+) T cells, leading to the tenet that CD8(+) T cells play a passive role in their own differentiation. In contrast, by using a DNA vaccination model, to separate the events of vaccination from those of CD8(+) T cell priming, we demonstrate that CD8(+) T cells, themselves, actively limit their own memory potential through CD8(+) T cell-derived IFN-gamma-dependent modification of the IL-12/IL-15R alpha axis on DCs. Such CD8(+) T cell-driven cytokine alterations result in increased T-bet and decreased Bcl-2 expression, and thus decreased memory progenitor formation. These results identify an unrecognized role for CD8(+) T cells in the regulation of their own effector differentiation fate and a previously uncharacterized relationship between the balance of inflammation and memory formation. The Journal of Immunology, 2012, 188: 3639-3647.