Activation and proliferation signals in murine macrophages: Synergistic interactions between the hematopoietic growth factors and with phorbol ester for DNA synthesis

Abstract

There has been recent interest in the synergistic interactions between the growth factors involved in the in vitro control of hematopoiesis and other cell lineages. As a convenient model system, such interactions governing the DNA synthesis in murine bone marrow-derived macrophages (BMMs) were studied. By themselves, murine colony-stimulating factor-1 (CSF-1) and recombinant murine granulocyte-macrophage CSF (GM-CSF) were stimulators of DNA synthesis in quiescent or noncycling BMMs, whereas recombinant murine interleukin-3 (IL-3) and the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), where weak mitogens. On the other hand, murine granulocyte CSF (G-CSF), concanavalin A (Con A), ..