Complement receptor phenotypes of culture-derived murine macrophages

The distribution of complement receptors CR1 and CR3 among macrophages derived from cultures of bone marrow, blood, and elicited or normal peritoneal cell populations was studied. Cells and colonies from the first three sources had a common phenotype, CR1+3-, whereas those from the normal peritoneal populations had either CR1+3- or CR1+3+. The former phenotype characterized spindle-shaped as well as epithelial-like macrophages; the latter was essentially restricted to colonies made up of the epithelioid cells. Both morphologic features and the CR phenotypes remained stable throughout the culture period. These phenotypic differences might be explained by the presence of at least two clonally derived types of macrophages.