In vitro proliferation of mononuclear phagocytes from murine and human bone marrow

Techniques for liquid culture of proliferating mononuclear phagocytes from bone marrow of mice and men are described. Mouse bone marrow must be cultured in the presence of colony-stimulating factor, whereas proliferation of human mononuclear phagocytes occurred in medium with 50% serum but without colony-stimulating factor. The number of mononuclear phagocytes that can be determined in mouse bone marrow cultures is higher than that in cultures of human bone marrow. However, the number of mononuclear phagocytes found for the human system is an underestimation, because the immature mononuclear phagocytes cannot be recognized at the light-microscopical level. These precursor cells (monoblasts and promonocytes) can be recognized with the electron microscope. The characteristics of the various types of mononuclear phagocyte, especially in cultures of murine bone marrow, are reviewed.