Roles of RUNX Complexes in Immune Cell Development.

During hematopoiesis, a variety of cells are generated from stem cells through successive rounds of cell fate determination processes. Studies in the last two decades have demonstrated the involvement of Runx transcription factor family members in differentiation of multiple types of hematopoietic cells. Along with evolutionary conservation, the Runx family is considered to be one of the ancestral regulators of hematopoiesis. It is conceivable that the Runx family is involved in shaping the immune system, which is then comprised of innate and acquired lymphoid cells in vertebrates. In this chapter, we will first summarize roles of Runx proteins during the development of T- and B-lymphocytes, which appeared later during evolution and express antigen specific receptors as a result of DNA recombination processes. We also discuss the recent findings that have unraveled the functions of Runx during differentiation of innate lymphoid cells (ILCs).