Epitope patterns of anti-RNP antibodies in rheumatic diseases. Evidence for an antigen-driven autoimmune response.
Autoantibodies against small nuclear ribonucleoproteins (snRNP) are common in systemic lupus erythematosus and related disorders. The 3 categories, anti-(U1)RNP, anti-(U1, U2)RNP, and anti-Sm, all contain a common antibody specificity directed against the U1 snRNP-associated A protein. To determine the specificity of anti-U1 snRNP A protein antibodies for various antigenic sites, we tested 26 different anti-snRNP-positive sera for reactivity with fragments of the U1 snRNP A protein, which was produced using recombinant DNA technology. Several different fragments were shown to contain autoimmune-reactive epitopes, which indicates that the antibody response against the U1 snRNP A protein is polyclonal. Antibodies against a discontinuous or conformational epitope were found in most of the sera tested, regardless of whether they were classified as anti-(U1)RNP, anti-Sm, or anti-(U1, U2) RNP. These results strongly support the hypothesis that the anti-snRNP autoimmune response is antigen driven.
Habets
W J
WJ
Department of Biochemistry, University of Nijmegen, The Netherlands.
Hoet
M H
MH
van Venrooij
W J
WJ
D000974:Antibodies, Antinuclear / Q000235:genetics* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D002872:Chromosome Deletion; D000939:Epitopes / Q000235:genetics*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D009154:Mutation; D012216:Rheumatic Diseases / Q000276:immunology*; D012261:Ribonucleoproteins / Q000235:genetics / Q000276:immunology*; D017411:Ribonucleoproteins, Small Nuclear
D000974:Antibodies, Antinuclear; D001324:Autoantigens; D000939:Epitopes; D007106:Immune Sera; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear