Humans produce approximately 300 billion blood cells per day. Hematopoiesis is the process by which blood cells are made by transiting through a hierarchy of hematopoietic stem and progenitor cells (HSPCs). Hemopoietic stem cells (HSC) are defined by their ability to self-renew as well as differentiate into the progenitors that replenish the entire blood system. Residing at the top of this hierarchy, HSC are located in a number of embryonic niches, settling in the bone marrow (BM) in adult life. Contrary to previous assumptions, HSC are a heterogeneous cell population, and likely number tens of thousands of cells in adult life, giving rise to hundred of millions of hierarchically organised highly heterogeneous progenitor cells which in turn differentiate into precursor cells and eventually mature effector cells. Although the field of stem/progenitor cell biology has grown dramatically over the past decades, bone marrow transplantation (BMT) has been in routine clinical practice for >50 years and is the only routine widely used example of stem/progenitor cell therapy.
There are multiple groups in Oxford working on purifying and studying the biology of HSPC in multiple model species and in humans. Allied to this is a programme to understand how inherited and acquired mutations in key genes regulating HSPC biology work coordinately to cause human blood cancers and other human blood disorders such as common bone marrow failure syndromes and anaemias.