Epigenetics of Immune Function
Hematopoiesis is the lifelong regeneration of our blood cells; it produces far more cells than any other tissue of our body. Signal transduction pathways stimulated by growth factors regulate in combination with transcription factors and chromatin modifiers the self-renewal and differentiation of hematopoietic stem cells (HSCs). Most of the approximately 100 different blood cell types, which are generated by hematopoiesis, belong to the immune system and differ in their epigenetic programing, in particular at cell-specific enhancer regions. Epigenetic regulation is fundamental for the differentiation of immune cells, as well as for their adaptive response to several environmental challenges, such as microbe infections. These epigenetic processes are also the basis for trained immunity representing memory function of the innate immune system. In general, epigenetic profiling of immune cells is an important tool for a molecular description of health and diseases as different as allergic reactions and cancer.