Idiotypic analysis of a monoclonal anti-Sm antibody. II. Strain distribution of a common idiotypic determinant and its relationship to anti-Sm expression.
The idiotypes borne by Y2, a monoclonal anti-Sm antibody of MRL-lpr/lpr mouse strain origin, were investigated to elucidate genetic mechanisms in this autoantibody response. An anti-Y2 anti-idiotypic antiserum was raised in a rabbit and was rendered specific for idiotype by extensive absorption with globulins of the B6 and BALB/c strains as well as the BALB/c myeloma UPC 10. By using a sensitive assay for idiotype by inhibition ELISA, the Y2 determinant was found to be commonly expressed in sera of MRL-lpr/lpr and MRL-+/+ mice. Moreover, sera of several normal strain mice also bore the idiotype and, in mice bearing the lpr gene, idiotype levels were increased 1.5 to fivefold, even in the absence of a serum anti-Sm response. The relationship of this idiotype to anti-Sm expression was further assessed by determining the idiotype content of affinity-purified anti-Sm antibodies from MRL-lpr/lpr mice. Anti-Sm from serum pools or individual animals showed no significant enrichment of the Y2 idiotype in comparison to unselected MRL-lpr/lpr IgG. These results suggest that the Y2 idiotype defines only a minor component of the anti-Sm autoantibody response, and that most antibodies with this determinant express other antigenic specificities.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000235:genetics*; D000941:Antigens / Q000235:genetics / Q000276:immunology*; D001324:Autoantigens; D001666:Binding Sites, Antibody; D000939:Epitopes / Q000235:genetics*; D007130:Immunoglobulin Idiotypes / Q000235:genetics*; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008814:Mice, Inbred NZB; D008817:Mice, Mutant Strains; D011817:Rabbits; D017411:Ribonucleoproteins, Small Nuclear; D013045:Species Specificity; D055517:snRNP Core Proteins
D000911:Antibodies, Monoclonal; D000941:Antigens; D001324:Autoantigens; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins