Affinity of SSB/La nuclear antigen to small nuclear ribonucleic acids

Anti-SSB/La antibody is one kind of antinuclear antibody and is found predominantly in patients with Sjögren's syndrome and systemic lupus erythematosus. SSB/La antigen is present in the nucleus as ribonucleoprotein in particle form and is composed of peptide and RNAs. SSB/La antigen can be partially purified through several sequential procedures including salt fractionation and ion exchange chromatography. SSB/La antigen is capable of binding to 4 RNAs from uninfected KB cells and 6 RNAs from Epstein-Barr virus transformed WiL2 cells. These RNAs can bind to SSB/La peptide in vitro and form ribonucleoprotein complexes which could be reprecipitated by anti-SSB/La antibody. SSB/La associated RNAs are labile and subjected to degradation easily. Anti-SSB/La antibody may be a useful probe to investigate the potential role of Epstein-Barr virus involvement in cutaneous pathology.