Macrophage heterogeneity in bone marrow culture in vitro.

Macrophages in mouse bone marrow cultures were investigated with macrophage-specific monoclonal antibody F4/80 and anti-Forssman glycosphingolipid (GSL) antibody, which was specific for macrophages in hematopoietic foci. Antibody F4/80 stained two types of cells, small macrophages and large flat macrophages associated with hematopoietic cells. The cytochemical and phagocytotic characteristics were similar between these two types of cells, but Forssman GSL was positive only for the large flat macrophages associated with hematopoietic cells. The data suggest that Forssman GSL positive macrophages, derived from resident bone marrow macrophages, play an important role in hematopoiesis and are clearly distinguished from small macrophages in vitro.