DNA demethylation fine-tunes IL-2 production during thymic development and promotes Regulatory T cell differentiation

• Published in: The Journal of immunology (1950) 2023-05, Vol.210 (1_Supplement), p.76-76.24
• Main Authors: Issuree, Priya D, Teghanemt, Athmane, Heath, Jace, Thurman, Andrew, Pezzulo, Alejandro
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.210.Supp.76.24

Regulatory T (T reg) cells developing in the thymus are essential to maintain tolerance and prevent fatal autoimmunity in mice and humans. Expression of the T reg lineage-defining transcription factor FoxP3, is critically dependent upon T cell receptor (TCR) and interleukin-2 (IL-2) signaling. Here, we report that ten-eleven translocation (Tet) enzymes, which are DNA demethylases, are required early during double positive (DP) thymic T cell differentiation and prior to the upregulation of FoxP3 in CD4 single-positive (SP) thymocytes, to promote Treg differentiation. We show that Tet enzymes selectively control the development of CD25 −FoxP3 loCD4SPTreg cell precursors and are critical for optimal TCR-dependent IL-2 production, which drive chromatin remodeling at the FoxP3 locus as well as other Treg-effector gene loci in an autocrine/paracrine manner. Together, our results demonstrate a novel role for DNA demethylation in regulating the TCR response and promoting Treg cell differentiation. These findings highlight a novel epigenetic pathway to promote the generation of endogenous Treg cells for mitigation of autoimmune responses.