The IL-7 Receptor Controls the Accessibility of the TCRγ Locus by Stat5 and Histone Acetylation

The IL-7 receptor (IL-7R) plays critical roles in expansion and V(D)J recombination during lymphocyte development. Here we demonstrate that cytokine stimulation rapidly recruits Stat5 and transcriptional coactivators to the Jγ germline promoter and induces histone acetylation, germline transcription, and accessibility in Ba/F3 cells. We also show that histone acetylation of the TCRγ locus is significantly reduced in IL-7R-deficient thymocytes and that the introduction of active Stat5 restores the histone acetylation and accessibility of the locus. Furthermore, treatment with histone deacetylase inhibitor recovers the histone acetylation and accessibility in IL-7R-deficient thymocytes. Therefore, these results suggest that Stat5 may recruit the transcriptional coactivators to the Jγ germline promoter and control the accessibility of the TCRγ locus by histone acetylation.