Our group works on developing methods for successful transplantation of blood stem cells to treat fetuses with genetic disorders such as sickle cell disease or thalassemia. In this grant, we are using novel stem cells that will differentiate into blood-forming cells and other techniques to improve the “engraftment” of these cells. Our strategies involve using antibodies to deplete stem cell from the fetal host to create “space” in the bone marrow for the engraftment of the newly transplanted cells. A second strategy involves co-transplanting regulatory T cells, which may prevent an immune response against the transplanted cells. The clinical applications of our work would involve performing stem cell transplant in fetuses with inherited blood stem cell disorders so that they can be born healthy.