Antibody-dependent cellular cytotoxicity against tumor cells. II. The promonocyte identified as effector cell.
Macrophage precursor cells were cultured from the bone marrow of mice in a liquid culture system in the presence of conditioned medium. To separate their different maturation stages, they were passed through a discontinuous Ficoll density gradient, treated with iron plus magnet or passed through glass bead columns. The different maturation stages have been tested for their function in antibody-dependent cellular cytotoxicity (ADCC) against tumor target cells and in lymphokine-induced macrophage-mediated cytotoxicity. It is shown that the promonocyte, a nonadherent, nonphagocytic precursor cell, is a highly potent cytotoxic effector cell against antibody-coated tumor targets but is totally inactive as an effector cell in lymphokine-induced macrophage-mediated cytotoxicity. In contrast, in the lymphokine-induced macrophage-mediated cytotoxicity the cytotoxic effector cell is a mature macrophage. Thus, ADCC seems to be a function of the macrophage precursor promonocytes, whereas lymphokine-induced cytotoxicity is performed by mature macrophages. The relationship of promonocytes and killer (k) cells in ADCC against tumor targets is discussed.
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D001853:Bone Marrow / Q000276:immunology; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D005260:Female; D008222:Lymphokines / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000276:immunology*; D009374:Neoplasms, Experimental / Q000276:immunology*; D011817:Rabbits; D013154:Spleen / Q000276:immunology
D008222:Lymphokines