GSE136648
Evaluation of Genome-wide chromatin accessibility of BM T cell subsets [ATAC_TC]
Chromatin accessibility of bone marrow conventional T cells, pTregs, tTregs, BMAC-induced Tregs and in vitro-induced Tregs were compared Bone marrow (BM) harbors a large repertoire of regulatory T (Treg) cells, which    are essential in hematopoiesis and peripheral tolerance. Treg cell accumulation    in BM has been viewed as a consequence of preferential immigration of    thymus-derived Treg cells. Here we report a novel subset of antigen presenting    cells, which expresses the autoimmune regulator (Aire). These BM    Aire-expressing cells resemble a subset of CD138+B220-TACI+Blimp-1+MHC-II+    plasma cells (pc-BMACs) and express a diverse repertoire of tissue-restricted    self-antigens. pc-BMACs present self-antigens to na  ve CD4+ T cells and can    efficiently convert these into functionally competent CD25+Foxp3+ bona fide    peripheral Treg cells (pTregs) capable of exerting immune suppression in vitro    and in vivo. Aire expression may contribute to the tolerogenic function of    pc-BMACs as it regulates the expression of genes involved in pTreg induction    and function, including Icosl and retinoic acid synthesis-related genes,    Aldh1a2 and Aldh1b1. Our data thus demonstrate an Aire-expressing plasma cell    subset in the BM capable to promote peripheral tolerance by ectopically    expressing tissue-restricted self-antigens and generating pTregs. Overall design: 6.5TCR (HA-specific CD4) T cells were transferred into Aire-HA host and bone marrow T cell subsets were sorted 14 days post transfer for comparison of their chromatin accessibility