The genetic regulation of immune cells upon activation

Recent discoveries in the field of epigenetic regulation have shed light on the intricate processes of immune cell activation, differentiation, and function in response to threats. Epigenetics connects genetic and environmental factors and includes DNA methylation, histone post-translational modifications and the regulation of chromatin accessibility by non-coding RNAs controlling constitutive or inducible gene transcription. These mechanisms coordinate the activation or suppression of immune cells via specific transcriptional programmes. In particular, epigenetic marks at the sites of lineage-specific transcription factors, as well as the maintenance of cell-type-specific epigenetic modifications, dictate cell differentiation, cytokine production and functional ability following repeated exposure to antigens in memory T cells. Furthermore, the epigenetic and metabolic reprogramming that occurs during a primary innate immune response, results in enhanced responses to secondary challenges. A complete understanding of the epigenetic basis of immune cell differentiation and cellular stability will clarify pathological dysregulation and help delineate new therapeutic strategies for targeting immune disorders.