Elucidating fetal haematopoiesis in mouse and human

Hematopoiesis is a finely tuned process by which mature blood cells of multiple lineages are constantly generated throughout life from hematopoietic stem cells. In humans, definitive hematopoiesis commences in the fetal liver (FL) at around five weeks of gestation, and remains the main site of hematopoiesis throughout fetal life. Hematopoiesis in the bone marrow (BM) starts around 11-12 weeks of gestation, but does not take over as the primary site of hematopoiesis until just after birth. Recent evidence suggests that fetal hematopoiesis is distinct from postnatal hematopoiesis in many ways. Most of these studies have been done on mouse models, but whether these differences exist in, or are a true reflection of hematopoiesis in the human setting, remains to be determined. We, and others have begun to investigate unique features of human fetal hematopoiesis and this project will determine fetal specific programmes that change through ontogeny. This may depend on the physiological processes or demands of that particular developmental stage, and/or in response to specific microenvironmental cues. This research is clinically relevant since the transplantation of hematopoietic stem cells from donors of different ages vary in their regenerative and differentiation potential. Studying hematopoiesis throughout the human lifespan may be important not only to understand normal developmental processes, but also to understand the pathogenesis of postnatal haematological diseases that may have their origins in fetal life. Research by the Roy laboratory particularly focuses on properties of fetal cells that contribute to leukemia initiation in utero and how these might change after birth, and we have recently developed a unique infant acute lymphocytic leukemia (ALL) model. We are particularly interested in ‘oncofetal’ genes that might define the biology of infant and childhood leukemias; and whether they can be manipulated for therapeutic interventions.

*This project is available for the 2021 Oxford-NIH Pilot Programme*