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.