B cell apotopes of the 60-kDa Ro/SSA and La/SSB autoantigens.
Apoptosis has been proposed to influence the initiation and diversification of autoimmunity to the Ro (SSA)/La (SSB) ribonucleoprotein (RNP) particle and serve as a target for autoantibody-mediated tissue injury. We have developed a new approach to B cell epitope mapping which identifies "apotopes," defined as epitopes expressed on the surface of apoptotic cells. Preliminary studies support a role for apotopes as diagnostic markers in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome. For example, apotopes within the NH(2)-terminal and central regions of La react with the majority of sera from mothers of infants with congenital heart block. Furthermore, a Ro60 apotope is specific for a subset of SLE with isolated anti-Ro60 responses. The mapping of B cell apotopes may prove superior to standard epitope mapping by suggesting novel pathways of autoantibody production and identifying pathogenic species of autoantibodies.
Reed
Joanne H
JH
Department of Immunology, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia. joanne.reed@flinders.edu.au
Jackson
Michael W
MW
Gordon
Tom P
TP
D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000276:immunology*; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D006801:Humans; D020733:RNA, Small Cytoplasmic / Q000276:immunology*; D012261:Ribonucleoproteins / Q000276:immunology*; D000097585:SS-B Antigen; D000099207:SS-A Antigen
D001323:Autoantibodies; D001324:Autoantigens; D018985:Epitopes, B-Lymphocyte; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000097585:SS-B Antigen; C116006:RO60 protein, human; D000099207:SS-A Antigen