Pim1 permits generation and survival of CD4+ T cells in the absence of γc cytokine receptor signaling.

γ-Chain (γc) cytokine receptor signaling is required for the development of all lymphocytes. Why γc signaling plays such an essential role is not fully understood, but induction of the serine/threonine kinase Pim1 is considered a major downstream event of γc as Pim1 prevents apoptosis and increases metabolic activity. Consequently, we asked whether Pim1 overexpression would suffice to restore lymphocyte development in γc-deficient mice.

CD8 lineage-specific regulation of interleukin-7 receptor expression by the transcriptional repressor Gfi1.

Interleukin-7 receptor α (IL-7Rα) is essential for T cell survival and differentiation. Glucocorticoids are potent enhancers of IL-7Rα expression with diverse roles in T cell biology. Here we identify the transcriptional repressor, growth factor independent-1 (Gfi1), as a novel intermediary in glucocorticoid-induced IL-7Rα up-regulation.