Autoimmune response to the Ro/SSA particle is directed to the human antigen
Reichlin, M.; Rader, M.; Harley, J.B.
Clinical and Experimental Immunology 76(3): 373-377
1989
ISSN/ISBN: 0009-9104 PMID: 2473859 Document Number: 328917
Autoantibodies to defined cellular antigens in systemic lupus erythematosus (SLE) are usually directed to conserved epitopes on ubiquitous macromolecules including histone, Sm + nRNP (URNP particles), DNA, and La(SSB). We report here that the autoimmune response to the Ro(SSA) RNA protein particle is directed to epitopes on the human antigen which are not conserved in evolution. Ro(SSA) from bovine, rat, and mouse Ro(SSA) particles cross-react with human autoantibodies less effectively than does human Ro(SSA), and antigenically active Ro(SSA) is not detectable in chicken thymus extracts with the assays employed. These data suggest a special role for the Ro(SSA) antigen in the initiation and/or perpetuation of the anti-Ro(SSA) response in autoimmune disease.