title: Binding of monoclonal IgM rheumatoid factor to streptococci via the antibody combining site.
abstract: Radiolabelled monoclonal IgM rheumatoid factors, four from patients with type II essential cryoglobulinaemia and one originating from a patient with rheumatoid arthritis, were tested for binding to group A, B, C and G streptococci and Escherichia coli. Two of the preparations exhibited different binding patterns for the streptococci, whereas the remaining three were not reactive. The binding of one of the factors to group A streptococci type 15 was inhibited by F(ab')2-fragments of anti-idiotypic antibodies but not anti-IgM Fc or F(ab')2 of normal rabbit IgG, indicating that the reaction was mediated via the antibody combining sites.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000915:Antibody Affinity; D001666:Binding Sites, Antibody; D003449:Cryoglobulinemia / Q000097:blood; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology* / Q000378:metabolism; D008722:Methods; D011817:Rabbits; D011961:Receptors, Fc / Q000276:immunology; D012217:Rheumatoid Factor / Q000276:immunology* / Q000378:metabolism; D013291:Streptococcus / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D007075:Immunoglobulin M; D011961:Receptors, Fc; D012217:Rheumatoid Factor