Epigenetics of T cells regulated by Polycomb/Trithorax molecules

•T cells are epigenetically regulated throughout their lifespan.•PcG proteins play roles in thymocyte development.•T cells use PcG proteins to prevent inadequate immune responses.•TrxG proteins are essential for the cellular memory of T cells.

Epigenetics provides a bridge between genetic and environmental factors, and can change the transcriptional outcome of a gene without changing the genomic sequence. Allergies and autoimmune diseases are caused by both of these factors, and dynamic changes in epigenetic marks have been reported in T cells, which are key players in the pathogenesis of immune-mediated diseases. Advances in technology, including gene knockout systems and high-throughput sequencing, have significantly enhanced the understanding of the lifespan of T cells, including maturation, differentiation and memory formation. In this review, we focus on Polycomb and Trithorax proteins, well-characterized epigenetic modulators, and discuss their role in the epigenetic regulation of T cell differentiation and function.