A heterogeneous immune response to an SmD-like epitope by SLE patients.
Two mouse cDNA clones were isolated by immunoscreening with an SLE serum. These clones encode an epitope which consists of a di-peptide repeat (Gly-Arg)n (n = 9 and 19 in isolated clones). These sequences, when expressed as fusion proteins, inhibit the binding of antibodies from one patient's serum to the SmD autoantigen. This cross-reactivity is based on the sequence identity with the carboxyterminal end of the human SmD [(Gly-Arg)g]. An Exonuclease III deletion analysis demonstrates that the minimal number of Gly-Arg repeats necessary for immune recognition on the Western blot is patient-specific, and varies from nine to three. The defined epitope is recognized by 35% of sera from patients with SLE as well as with other autoimmune diseases (rheumatoid arthritis, scleroderma, Sjogren's syndrome), in contrast to SLE-specificity of anti-Sm antibodies. Affinity-purified antibodies of the identified epitope cross-react with EBNA1 protein in EBV-infected B-cell lines.
Rivkin
E
E
Department of Medicine, St Luke's/Roosevelt Hospital Center, Columbia University, New York, NY.
Vella
M J
MJ
Lahita
R G
RG
D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000096:biosynthesis / Q000276:immunology*; D001483:Base Sequence; D002460:Cell Line; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology; D006801:Humans; D015151:Immunoblotting; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D001323:Autoantibodies; D001324:Autoantigens; D000939:Epitopes; D011993:Recombinant Fusion Proteins; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins