Cultivation of macrophages derived from human malignant effusions.

Macrophages, isolated from malignant effusions, were cultured in vitro in media containing GCT/CM as a source of granulocyte-macrophage (GM) colony-stimulating factor (CSF). Cells were periodically examined for macrophage-specific cell surface antigens and functional activity. The number of macrophages increased sixfold during 15 days in culture. Autoradiographic studies confirmed that macrophages were incorporating 3H-Tdr. Macrophage-specific cell surface markers were retained up to five weeks in culture. Cells were also able to express macrophage-specific functions including phagocytosis and secretion of lysozyme. The results indicate that human tumor-derived macrophages may be expanded in short-term culture in the presence of GM CSF.