Feline complement dependent binding in the Raji cell assay is insufficient for the quantitation of immune complexes.
A comparison was made of the binding of radiolabeled heat aggregated cat immunoglobulin G (125I-ACG) to Raji cells using normal or heat-inactivated cat or human serum. The binding with normal or heated cat serum, as well as heated human serum were essentially identical. The binding using normal human serum was 2.5- to 3-fold greater than observed with heated human serum. These results suggest that feline complement associated with 125I-ACG does not bind to Raji cells via complement receptors, but only by receptors for the Fc portion of IgG. Human serum and 125I-ACG can bind to both Fc and complement receptors on Raji cells.
D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis*; D001666:Binding Sites, Antibody; D002051:Burkitt Lymphoma; D002415:Cats; D002460:Cell Line; D003165:Complement System Proteins / Q000276:immunology*; D006358:Hot Temperature; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology*; D007457:Iodine Radioisotopes; D011951:Receptors, Complement / Q000276:immunology; D011961:Receptors, Fc / Q000276:immunology; D013045:Species Specificity
D000936:Antigen-Antibody Complex; D007106:Immune Sera; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes; D011951:Receptors, Complement; D011961:Receptors, Fc; D003165:Complement System Proteins