Figure 2
From: Transcriptional regulation and development of regulatory T cells
Schematic diagram of Treg cell development. tTreg cells develop in the thymus by two-step process. First, high-affinity tissue-restricted self-antigens presented by medullary thymic epithelial cells (mTECs) or bone-marrow derived antigen-presenting cells (BM-APCs) derive single-positive (SP) T cells into Treg pathway. Second, cytokine IL-2 or IL-15 derives the precursor cells into fully committed tTreg cells. pTreg cells develop in the periphery by environmental antigens such as microbial antigens or food antigens presented by mucosal tissue-resident dendritic cells (DCs). TGF-β, retinoic acids (RAs) and short chain fatty acids (SCFAs) produced in the immunosuppressive environments promote pTreg development.
