GSE168829
A distal Foxp3 enhancer enables interleukin-2 dependent thymic Treg cell lineage commitment for robust immune tolerance [RNA-seq]
STAT5 transcription factor activation downstream of the Interleukin-2 receptor (IL-2R) induces expression of Foxp3, a critical step in the differentiation of regulatory T (Treg) cells. Due to the pleiotropic outputs of IL-2R signaling, it is unclear whether STAT5 acts directly on the Foxp3 locus to promote its expression . Here, we report that IL-2 – STAT5 signaling converged on an enhancer (CNS4) during Foxp3 induction. CNS4 facilitated and sustained the IL-2 dependent CD25+Foxp3– precursor to Treg cell transition in the thymus. Its deficiency resulted in markedly impaired Treg cell generation in neonates, which was partially mitigated with age. While the thymic Treg cell paucity caused by CNS4 deficiency did not result in autoimmunity on its own, it exacerbated autoimmune manifestations caused by disruption of the Aire gene. Thus, CNS4 enhancer activity ensures robust Treg cell differentiation early in postnatal life and cooperatively with other tolerance mechanisms, minimizes autoimmunity. Overall design: Regulatory T cells sorted from age- and sex-matched male and female CNS4-sufficient and -deficient mice were subjected to RNA sequencing to uncover the differential gene expression.