FLT-3 ligand promotes long- term expansion and
differentiation of human pro-B-cells in the presence of IL-7 or in combination
of IL-7 and IL-3.The human FLT-3 ligand also stimulates the proliferation of
cells expressing murine FLT-3 receptors. In combination with SCF and IL-3,
FLT-3 ligand can cause expansion of cells with the marker spectrum CD34（+）
CD38（-）. Alone, FLT-3 ligand supports the survival of precursors in the lineage
of blood-forming cells such as CFU-GM, CFU- GEMM, and the very primitive high
proliferative potential colony-forming cells, HPP- CFC. flt-3 ligand only has
marginal effects on progenitors for erythroid cells and megakaryocytes.