Priming for Th2 differentiation requires IL-2-mediated induction of IL-4 receptor alpha chain expression

Th2 cells enable humoral immunity and host-defense to parasites. Whereas IL-4 drives Th2 differentiation and IL-2 is important later in this process by augmenting IL4 chromatin accessibility, we demonstrate that IL-2 serves an essential early role in regulating IL-4Rα expression by inducing binding of Stat5a and Stat5b to the IL4ra locus, with sustained binding during Th2 differentiation. Although IL-4 induces IL-4Rα expression, TCR-induced IL-4Rα expression was unexpectedly normal in ILr-/- but profoundly diminished in IL2-/- T cells. Remarkably, enforced IL-4Rα expression rescued Th2 differentiation in IL2-/- cells. These results reveal a novel function for IL-2, with IL-2 via Stat5 providing an early signal for IL4ra induction, thereby priming cells for Th2 differentiation and promoting/maintaining IL-4Rα expression in Th2-committed cells. ChIP-seq experiments for Stat5a and Stat5b with an IgG control experiment for 8hr, 13hr and 2 rounds of Th2 differentiation. Keywords: ChIP-seq, Illumina, Th2 differentiation, Stat ChIP-seq experiments for Stat5a and Stat5b with an IgG control experiment for 8hr, 13hr and 2 rounds of Th2 differentiation. There are a total of 22 lanes of data for the three samples across the three time points.