Measurement of immunoglobulin binding to synovial fibroblast monolayers: comparison of staphylococcal protein A binding to cytotoxic assay methods.
We have studied the binding of rabbit antibody to cultured synovial fibroblasts by 3 methods: complement mediated cell lysis, 125I-labeled staphylococcal protein A ([125I]PrA) and antibody dependent cell mediated cytotoxicity (ADCC). The relative sensitivities of these 3 methods is 1 : 33 : 3300 respectively. The [125I]PrA binding method is shown to quantitatively detect cell bound IgG with a molar stoichiometry of approximately 1 : 1, protein A (PrA) to IgG if PrA is present in excess.
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D000954:Antigens, Surface; D001666:Binding Sites, Antibody; D002417:Cattle; D003602:Cytotoxicity, Immunologic; D005347:Fibroblasts / Q000276:immunology; D007074:Immunoglobulin G / Q000302:isolation & purification; D008297:Male; D008433:Mathematics; D011817:Rabbits; D013205:Staphylococcal Protein A / Q000276:immunology*; D013583:Synovial Membrane / Q000276:immunology*
D000954:Antigens, Surface; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A