Characterization of subsets of bone marrow-derived macrophages by flow cytometry analysis.
Normal C3H bone marrow cells were grown 7 days in medium containing L cell-derived colony stimulating factor-1 (CSF-1). During the first 4 days of culture, erythroid and granulocytic cells decreased while macrophages increased exponentially with a doubling time of about 31 hr. Only 0.3% of all cells in the initial bone marrow suspension formed discrete colonies of mononuclear phagocytes, but by day 6 60% of the nonadherent cells were capable of forming macrophage colonies, representing a 200-fold enrichment of the original progenitor population. Using flow cytometry, mononuclear phagocytes obtained after 4 days of culture were separated into two distinct phenotypes based on their autofluorescence. Nonadherent cells were a discrete population of small cells exhibiting low autofluorescence, and the adherent cells were a broad heterogeneous population of large cells exhibiting high autofluorescence. A panel of currently available rat monoclonal antibodies (MABs) against murine hematopoietic cells were used to determine whether unique subsets of macrophages could be resolved. The MABs RA 31B6 and H-11 stained virtually all the nonadherent cells but not adherent cells. The MABs E-2 and 11-4.1 (anti-H-2Kk) stained almost all the adherent cells and demonstrated no significant staining of nonadherent cells. Nearly all the nonadherent and adherent cells were stained by the MABs DNL 4.4 and MAC-1. Additionally, the data suggest that the epitopes for MAC-2 and MAC-3 and gamma 2a Fc receptors develop late in nonadherent progenitor cells as they mature into adherent macrophages.
D000818:Animals; D000911:Antibodies, Monoclonal; D001854:Bone Marrow Cells; D002448:Cell Adhesion; D002454:Cell Differentiation; D002478:Cells, Cultured; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D007124:Immunoenzyme Techniques; D008264:Macrophages / Q000145:classification* / Q000166:cytology / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D010641:Phenotype; D051381:Rats
D000911:Antibodies, Monoclonal