The study of immune cell development by stem cell mutagenesis. (360G-Wellcome-100083_Z_12_Z)

This proposal applies embryonic stem cell mutagenesis in vitro, and somatic mutagenesis of hematopoietic stem cells in vivo, to understand pathways of immune cell differentiation. The first approach involves the creation of recessive mutations in mouse haploid embryonic stem cells, which will then be differentiated into myeloid and lymphoid cells in vitro. A second complementary approach involves the development of a cre-inducible conditional mutagenesis system. By triggering a self-inactivating transposition event in immune cell progenitors, we can trace the inheritance of mutations throughout immune cell lineages in vivo. In both approaches, comparative deep sequencing will be used to reveal mutations that are selectively absent from differentiated subsets. These mutations will improve our understanding of immune cell development in health and disease, while the genetic systems we develop will be broadly applicable to the study of cellular differentiation.