Isolation of variants in phagocytosis of a macrophage-like continuous cell line.
We have isolated cloned variants in phagocytosis from a cloned continuous murine macrophage-like cell line, J 774.2. A selection procedure against Fc receptor-mediated phagocytosis was devised using IgG-coated SRBC containing a toxic drug, tubercidin, as the lethal agent. A series of variant clones deficient in Fc receptor-mediated phagocytosis were isolated. Such variants occurred at low frequency (approximately 6 X 10(-5)), were stable, and appeared to possess Fc receptors. The degree to which they were defective in phagocytosis of IgG-coated SRBC varied from clone to clone, yet all clones, were able to phagocytize latex particles. The phagocytic defect in some variants could be corrected by the addition of 8 Br-cAMP, in others, the drug was without effect. It is likely, therefore, that different variants are defective in several distinct steps critical to Fc receptor-mediated phagocytosis.
D001665:Binding Sites; D002460:Cell Line; D002469:Cell Separation; D002999:Clone Cells / Q000502:physiology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D007141:Immunoglobulin Fc Fragments; D008264:Macrophages / Q000502:physiology*; D009895:Opsonin Proteins; D010587:Phagocytosis / Q000187:drug effects; D012408:Rubber; D014372:Tubercidin
D007141:Immunoglobulin Fc Fragments; D009895:Opsonin Proteins; D012408:Rubber; D000242:Cyclic AMP; D014372:Tubercidin