title: Antibodies to the Epstein-Barr virus nuclear antigen and to rheumatoid arthritis nuclear antigen identify the same polypeptide.
abstract: Patients with seropositive rheumatoid arthritis (RA) have elevated titers of precipitating antibody toward an antigen designated RA nuclear antigen (RANA). Anti-RANA reactivity has been associated with prior Epstein-Barr virus (EBV) infection. Using the protein blot technique, we have identified, in extracts of WI-L2, an EBV+ nonproducer B-lymphoblast line, a Mr 80,000 polypeptide that is reactive with anti-RANA-containing sera. This same polypeptide can be recovered from RANA precipitin bands. The Mr 80,000 polypeptide appears to be EBV-associated, as a homologous antigen was detected in two other EBV+ cell lines, Daudi and Raji, but was not present in three EBV- human cell lines tested, HeLa, BJAB, and Ramos. Anti-RANA antibodies and antibodies reactive with the Mr 80,000 polypeptide also appear coincidently in the sera of individuals exhibiting an EBV infection (infectious mononucleosis). Further analysis of the RANA-associated Mr 80,000 polypeptide suggested its identity with the previously recognized EBV-associated nuclear antigen designated EBNA. The Mr 80,000 antigen shares with EBNA the properties of being a heat-stable, DNA binding protein. EBNA is traditionally assayed by a complement fixation reaction and anti-Mr 80,000 antibodies were shown to be reactive when a complement fixation assay was used in the immunoblot. Finally, when the Mr 80,000 antigen was used to absorb an anti-RANA/anti-EBNA serum, both antibodies were reduced.
mesh_terms: D000745:Anemia, Hemolytic, Congenital; D000914:Antibodies, Viral / Q000276:immunology*; D000941:Antigens / Q000032:analysis*; D034961:Antigens, Nuclear; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D002051:Burkitt Lymphoma; D002460:Cell Line; D003168:Complement Fixation Tests; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D008970:Molecular Weight; D009698:Nucleoproteins / Q000032:analysis*
chemical_list: D000914:Antibodies, Viral; D000941:Antigens; D034961:Antigens, Nuclear; D009698:Nucleoproteins