Batf stabilizes Th17 cell development via limiting STAT5 signaling pathway (ChIP-Seq)

Th17 cells secrete IL-17A, IL-17F, IL-21, and IL-22 cytokines that are critical in mediating inflammation and protecting the host from microorganisms infection. The basic leucine zipper transcription factor ATF-like (Batf) contributes to the transcriptional programming of multiple effector T cells, and is required for Th17 cell development. Here, we have interrogated mechanisms by which Batf promotes and stabilizes Th17 cell phenotype. We have shown that in vitro differentiated Th17 cells have increased expression of Th1 and Treg signature genes in the absence of Batf. In addition, Citrobacter rodentium infected Batf-deficient (Batf KO) mice fail to clear the infection, and that is correlated with diminished IL-17A and IL-22 cytokine production and increased Foxp3 and Ifng expression compared to WT mice. We find that Batf sustains Th17 phenotype in long-term culture conditions by suppressing Th1- and Treg-specific gene expression. Mechanistically, we reveal that Batf negatively regulates IL-2-STAT5 signaling and modulates STAT5 binding at the Ifng and Foxp3 gene loci thus suppressing Th1-Treg phenotype in Th17 cell development. Inhibition of STAT5 DNA binding activity in Batf KO Th17 cells was able to repress Ifng and Foxp3 expression compared to control-treated cells. Moreover, STAT5 cooperates with transcription factors Ets1 and Runx1 to mediate epigenetic modification and regulate gene expression. Thus, our study has revealed an essential function of Batf in modulating the IL-2-STAT5 signaling to promote and stabilize Th17 cell development. Overall design: Naïve CD4+ T cells isolated from spleen/lymph nodes WT and Batf KO mice were actiated under Th17 culture conditions. Cells were harvested on day 5 and used for ChIP-seq experiments