Factors in Long-Term Maintenance of Human Bone Marrow-Derived Colony-Forming Cells In Vitro

Human bone marrow cells cultured for 21 days in the presence of recombinant human interleukin-3 (IL-3) produced up to 28 times more colony-forming cells (CFC) than could be obtained from cultures stimulated with granulocyte colony stimulating factor (G-CSF) or granulocytemacrophage CSF (GM-CSF). 11-3-cultured cells retained a multipotent response to 11-3 in colony assays but were restricted to formation of granulocyte colonies in G-CSF and granulocyte or macrophage colonies in GM-CSF. Culture of bone marrow cells in 11-3 also led to accumulation of large numbers of eosinophils and basophils. These data contrast with the effects of G-CSF, GM-CSF. and 11-3 in seven-day cultures. Here both GM-CSF and IL-3 amplified