Epigenetic Control of Immune T Cell Memory

The main role of the immune system is to protect against infections caused by invading pathogens. The adaptive immune system is particularly important for protection against repeated exposure to pathogens, due to its ability to memorize antigens during an initial infection and then respond rapidly and strongly to subsequent antigen challenges from the same or a related pathogen. This system forms immunological memory. Most epigenetic studies in immunology have focused on analysis of differentiation of CD4 T subsets, key players in the adaptive immune system. However, the relationship between immunological memory and epigenetics has not been as well studied. In recent years, with the advancement of technology such as ChIP-seq or RNA-seq methods, the importance of epigenetic mechanisms in immunological memory is becoming apparent. This review outlines our understanding of how CD4 T cells acquire and maintain function during or after differentiation, using Th2 cells as a model. In addition, we summarize the general characteristics of memory T cells from the perspective of epigenetics and discuss the possibility of clinical application of epigenetic studies in immunology.