Separate Fc-receptors for immunoglogulins IgG2a and IgG2b on an established cell line of mouse macrophages.
The specificity of Fe-receptors on IC-21 cells, an established line of mouse peritoneal macrophages with antibody-dependent effector cell activity has been examined. Only IgG2a and IgG2b myeloma proteins bound readily to IC-21 Fc-receptors, the former in nonaggregated as well as aggregated form, the latter only as aggregated complexes. Thus, IgG2a bound in a manner characteristic of classically defined cytophilic antibody, whereas the binding of IgG2b appeared to be mediated by Fc-receptors for antigen-antibody complexes. Evidence is presented in support of the view that IC-21 macrophages possess separate and distinct Fc-receptor sites for these two immunoglobulins.
D000818:Animals; D000918:Antibody Specificity; D001666:Binding Sites, Antibody; D002460:Cell Line; D007141:Immunoglobulin Fc Fragments / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis*; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009194:Myeloma Proteins / Q000276:immunology; D010740:Phospholipases; D014357:Trypsin / Q000494:pharmacology
D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D009194:Myeloma Proteins; D010740:Phospholipases; D014357:Trypsin