The Swi/Snf chromatin remodeling complex promotes Th17 differentiation by coordinating RORγt-driven epigenetic program

TH17 cells play a critical role in mucosal immunity and also in multiple autoimmune diseases. The differentiation of TH17 cells is dictated by a master transcription factor, RORγt; however, the mechanism by which RORγt controls target genes is poorly understood. Here we identify the Swi/Snf chromatin remodeling complex as an essential regulator of TH17 cell differentiation. Loss of the expression of SRG3/mBAF155, a core subunit of the Swi/Snf complex, results in a specific downregulation of RORγt target genes such as IL-17A, IL-17F and IL-23R. Importantly, the comparative transcriptional analysis reveals a high similarity between RORγt and the Swi/Snf complex in the control of TH17-related gene expression. Mechanistically, the Swi/Snf complex partners with RORγt and coordinates a variety of RORγt–mediated epigenetic modifications, including both permissive and repressive ones. These results provide a basis for the understanding of how a master transcription factor RORγt cooperates with the Swi/Snf complex to govern the Th17 cell differentiation. WT, SRG3-deficinet and RORγt-deficinet naïve CD4+ T cells were cultured under Th17(β) conditions.