Immunophenotyping of human bone marrow-derived macrophages

In vitro cultured cells derived from human bone marrow stimulated with macrophage-colony stimulating factor (M-CSF) or granulocyte-macrophage-colony stimulating factor (GM-CSF) were investigated for their immunophenotypic surface characteristics by flow cytometry. Approximately 80-90% of the cells showed morphological and histochemical features of macrophages and bore CD11a, CD11b, CD11c, CD14, CD29, CD32, CD33, CD44, CD45, CD54, CD64, CD71, HLA-DR antigen. The expression of CD4, CD25 and CD45RO were detected only in low density. Bone marrow-derived macrophages were negative for CD8, CD45RA, CD16 and CD23. Functionally, macrophages were able to phagocytose opsonized Escherichia coli, but no oxidative bursts were induced either by fmlp or by opsonized bacteria. Cell surface phenotyping revealed a CD pattern very similar to monocyte-derived phagocytes, and was partially distinct from resident stromal macrophages.