[Monoclonal antibodies to polysaccharides of group A streptococci cross reacting with mammalian connective tissue].

Monoclonal antibodies (MCA) D 4/1 were obtained by immunization of BALB/c mice with group A streptococci treated with pepsin. MCA D 4/1 react in ELISA test with streptococcal group A, C, L, and A-variant (V) polysaccharides (PS). D 4/1 are autoantibodies, cross-reacting in immunofluorescent test with all the epithelial layers and fibroblast-like structures of human and BALB/c mouse skin. The MCA react also with the interstitial connective tissue of human, mouse and bovine myocardium and with the fibroblast cultures explanted from the skin of donors and rheumatic patients. Tissue reactions partially inhibited purified streptococcal group A, C and L PS, however, complete inhibition was obtained only with V PS. It is suggested that MCA D 4/1 are directed to CR-antigen, common for fibroblasts, all the layers of skin epithelium and one of the rhamnose determinants of group A polysaccharide.