Proliferative effect of interleukin-3 on normal and leukemic human B cell precursors

We have examined the influence of recombinant, human IL-3 on normal and leukemic B cell precursors. CD10/CALLA+ leukemic B cell precursors, the pre-B cell line BLIN-1, and surface IgM-B cell precursors isolated from fetal bone marrow all responded to IL-3. This IL-3 response was dose-dependent and could be abrogated by a rabbit anti-IL-3 antiserum. Binding studies using radiolabeled IL-3 revealed the presence of approximately 200 high affinity IL-3 receptors on the BLIN-1 cell line, with a KD of 150pM. We conclude that normal and leukemic human B cell precursors express functional IL-3 receptors, extending the biologic range of this hematopoietin to the lymphoid lineage.