Interferon-gamma binds to high and low affinity receptor components on murine macrophages.
Interferon-gamma (IFN-gamma), a glycoprotein secreted by antigen-or mitogen-activated lymphocytes, modulates the activities of lymphocytes and macrophages. For mouse macrophages, murine IFN-gamma (MuIFN-gamma) stimulates several functions, including phagocytosis, tumoricidal activity, and the increased expression of Ia and H-2 antigens of the major histocompatibility complex. Recent reports have suggested that IFN-gamma specifically binds to cell surface receptors corresponding to a single class of binding sites with a Kd of 10(-8) to 10(-10) M. We present evidence that, on the murine macrophage cell line WEHI-3, MuIFN-gamma specifically binds to two classes of binding sites with Kd of 9.1 X 10(-11) M (500 sites/cell) and 2.7 X 10(-9) M (4400 sites/cell). The higher affinity sites most likely represent the physiologically relevant receptors that mediate at least some of the actions of MuIFN-gamma.
D000818:Animals; D000918:Antibody Specificity; D001667:Binding, Competitive; D002460:Cell Line; D004306:Dose-Response Relationship, Immunologic; D007371:Interferon-gamma / Q000378:metabolism*; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011971:Receptors, Immunologic / Q000032:analysis*; D017471:Receptors, Interferon
D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D007371:Interferon-gamma