Induction of germline transcription in the TCR gamma locus by Stat5: Implications for accessibility control by the IL-7 receptor

IL-7 receptor (IL-7R) plays critical roles in lymphocyte development by pro moting survival and proliferation and by inducing V(D)J recombination in TC R and Ig loci. Here, we demonstrate that IL-7R-activated Stat5 binds to con sensus motifs in the 5' regions of J gamma segments and induces germline tr anscripts. We also show that a constitutively active form of Stat5 restores V-J recombination of TCR gamma genes and partially rescues T cell developm ent from IL-7R(-/-) T cell precursors, especially in favor of gamma delta T cells. Therefore, this study reveals a potential role of Stat5 in T cell d evelopment and also implies that IL-7R may control the accessibility of the TCR gamma locus through Stat5-induced germline transcription.