SWI/SNF chromatin-remodeling factor BAF60b restrains inflammatory diseases by affecting regulatory T cells migration [CUT&Tag]

Regulatory T (Treg) cells play a critical regulatory role in the immune system by suppressing excessive immune responses and maintaining immune balance. The effective migration of Treg cells is crucial for controlling the development and progression of inflammatory diseases. However, the epigenetic mechanisms responsible for directing Treg cells into the inflammatory tissue remain incompletely elucidated. In this study, we identified BAF60b, a subunit of SWI/SNF chromatin remodeling complexes, as a positive regulator of Treg cells migration that inhibits the progression of inflammation in experimental autoimmune encephalomyelitis (EAE) and colitis animal models. Mechanistically, transcriptome and genome-wide chromatin landscaped analyses demonstrated that BAF60b interacts with the transcription factor RUNX1 to promote the expression of CCR9 on Treg cells, which in turn affects their ability to migrate to inflammatory tissues. Our work provides insights into the essential role of BAF60b in regulating Treg cells migration and its impact on inflammatory diseases. To investigate the role of BAF60b in Treg cells, we established conventional BAF60b knockout mice. We isolated GFP+Treg cells from spleen of wild-type and BAF60b-deficient mice for CUT&Tag