A novel epitope on the C-terminus of SmD1 is recognized by the majority of sera from patients with systemic lupus erythematosus.

摘要: The SmD1 protein is a specific target for the autoantibody response in SLE. To further analyze this reactivity epitope, mapping was performed with cellulose-bound 13-mer peptides overlapping 10 amino acids (aa). In initial approach, 4 out of 15 SLE sera recognized more than five C-terminus. Therefore, longer oligopeptides up to 37 aa region were generated and probed as antigens by ELISA. For 83-119 polypeptide, there striking increase 70.0% positive reactions 167 sera. contrast, 105 healthy control negative, only 8.3% from patients other inflammatory diseases (n = 267) exhibited response, which low level only. anti-SmD183-119 significantly higher anti-dsDNA antibody vs. negative (P < 0.001) correlated disease activity. Four human monoclonal antibodies also reacted SmD183-119. specificity demonstrated inhibition experiments immunization rabbits SmD183-119 inducing SmD1-specific antibodies. conclusion, peptide be an important highly autoimmune high sensitivity ELISA probably depends on conformational appears not accessible full-size protein.