ESTABLISHMENT OF BONE-MARROW-DERIVED MACROPHAGE CELL-LINES BY SOFT-AGAR CLONING - REGULATION OF MACROPHAGE HETEROGENEITY AT BONE-MARROW LEVEL

To study the regulation of macrophage (m phi) heterogeneity at bone ma rrow level, we developed a liquid culture system in which bone marrow- derived soft-agar colonies were expanded in the presence of colony-sti mulating factor-1 (CSF-1). Several cloned m phi precursor cells were e stablished as CSF-1-dependent cell lines, and were analyzed for morpho logical, phenotypic and functional characteristics. The continuously p roliferating cell lines expressed both immature and mature m phi marke rs. Only minor differences between the established cell lines were det ected. Thus, our results show that during long-term culture CSF-1-resp onsive cloned m phi precursor cells develop along identical pathways, giving rise to progeny with comparable phenotype and function in vitro .