Proliferative effects of purified granulocyte colony‐stimulating factor (G‐CSF) on normal mouse hemopoietic cells

Abstract

When granulocyte colony‐stimulating factor (G‐CSF), purified to homogeneity from mouse lung‐conditioned medium, was added to agar cultures of mouse bone marrcw cells, it stimulated the formation of small numbers of granulocytic colonies. At high concentrations of G‐CSF, a small proportion of macrophage and granulocyte‐macrophage colonies also developed. G‐CSF stimulated colony formation by highly enriched progenitor cell populations obtained by fractionation of mouse fetal liver cells using a fluorescence‐activated cell sorter, indicating that G‐CSF probably acts directly on target progenitor cells. Granulocytic colonies stimulated by G‐CSF were small and uniform in size, and at 7 days of cu..