Single-cell chromatin accessibility landscape identifies tissue repair program in human regulatory T cells

Studies over the past decade characterized murine regulatory T cells (Tregs) with the capacity to promote tissue regeneration. In humans, such a population of tissue-repair Treg cells has not been discovered yet. Using single-cell chromatin accessibility profiles of murine and human tissue Treg cells, we defined a species-conserved and microbiota-independent repair Treg signature, with a prevailing footprint of the transcription factor BATF. Combining this signature with gene expression profiling and TCR fate mapping, we identified a population of tissue-like Treg cells in peripheral blood, characterized by the expression of BATF, CCR8 and HLA-DR. Human BATF+CCR8+ Treg cells from normal skin and adipose tissue shared features with tumor-resident Treg and tissue T-follicular helper (Tfh) cells. Inducing a Tfh-like differentiation program in naive Treg cells partially recapitulated human tissue Treg characteristics, including enhanced wound healing potentialEGA study EGAS00001004900