IL-2 and Related Cytokines Can Promote T Cell Survival by Activating AKT

The regulated elimination of T cells serves to maintain normal immune function and prevents autoimmune responses. IL-2 family cytokines play an important role in controlling the survival of immature and mature T cells. These molecules activate the protein kinase, AKT/PKB. AKT has been shown to transduce an antiapoptotic signal in numerous cell types. In this study, we show that an active form of AKT can protect T cells from apoptosis following growth factor withdrawal and that IL-2 family cytokines can promote T cell survival by activating this kinase. We also provide evidence that AKT does not block death receptor-mediated killing of lymphocytes. These data suggest that AKT may serve as a common signaling element by which members of the IL-2 family of cytokines promote T cell survival.