CYTOKINE STIMULATION OF MULTILINEAGE HEMATOPOIESIS FROM IMMATURE HUMAN-CELLS ENGRAFTED IN SCID MICE

Severe combined immunodeficient (SCID) mice transplanted with human bone marrow were treated with human mast cell growth factor, a fusion of interleukin-3 and granulocyte-macrophage colony-stimulating factor (PIXY321), or both, starting immediately or 1 month later. Immature human cells repopulated the mouse bone marrow with differentiated human cells of multiple myeloid and lymphoid lineages; inclusion of erythropoietin resulted in human red cells in the peripheral blood. The bone marrow of growth factor-treated mice contained both multipotential and committed myeloid and erythroid progenitors, whereas mice not given growth factors had few human cells and only granulocyte-macrophage progenitors. Thus, this system allows the detection of immature human cells, identification of the growth factors that regulate them, and the establishment of animal models of human hematopoietic diseases.