Anti-MHC immunity detected prior to intentional alloimmunization. III. Natural autoreactive H-2-specific antibodies.
Cell fusion was performed between spleen cells from young BALB/cBy (H-2d) mice which have never been immunized and SP2/0 mouse plasmacytoma cells. A monoclonal H-2 specific cytotoxic IgM antibody was obtained (By-1) which detected a new public biregional H-2 specificity, H-2.m210. The mcAb By-1 reacted strongly with H-2Kd, Dd, and H-2s antigens, gave weak cross-reactions with H-2Kk, Dq, H-2r, and H-2v antigens and was negative with H-2b, H-2f, H-2p, and H-2Ld antigens. A polymorphic reaction pattern was also observed on a panel of lymphocytes from B10.W strains. The intriguing finding on this reaction pattern was the reactivity on H-2d cells, including the syngeneic BALB/cBy and truly autologous cells. As shown by capping and immunoprecipitation experiments on H-2d cells and by studies on H-2d-transfected mouse L cells, the target molecules for McAb By-1 were H-2Kd and H-2Dd molecules. The BALB/cBy mouse, from whose spleen cells the McAb By-1 was obtained, survived after the fusion experiment, and serum was examined for the presence of cytotoxic H-2-specific antibodies during the rest of its life. At the time of the fusion, no autoreactive serum antibodies were found, but about 4 months later, we found in the serum of this mouse autoreactive H-2-specific cytotoxic IgM antibodies. The serum antibodies followed the same reaction pattern as that of the McAb By-1. As far as we know, this is the first report of autoreactive H-2-specific antibodies in serum of a mouse which has never been immunized and of the first natural autoreactive H-2-specific monoclonal antibody.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D006183:H-2 Antigens / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007114:Immunization; D007518:Isoantibodies / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D006183:H-2 Antigens; D007518:Isoantibodies