Rivkin E, Vella M J, Lahita R G
Department of Medicine, St Luke's/Roosevelt Hospital Center, Columbia University, New York, NY.
J Autoimmun. 1994 Feb;7(1):119-32. doi: 10.1006/jaut.1994.1009.
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.
通过用系统性红斑狼疮（SLE）血清进行免疫筛选，分离出两个小鼠cDNA克隆。这些克隆编码一种表位，该表位由一个二肽重复序列（Gly-Arg）n组成（分离出的克隆中n = 9和19）。这些序列以融合蛋白形式表达时，可抑制一名患者血清中的抗体与SmD自身抗原的结合。这种交叉反应性基于与人类SmD羧基末端[(Gly-Arg)g]的序列同一性。核酸外切酶III缺失分析表明，蛋白质印迹上免疫识别所需的Gly-Arg重复序列的最小数量因患者而异，从九个到三个不等。35%的SLE患者以及其他自身免疫性疾病（类风湿性关节炎、硬皮病、干燥综合征）患者的血清可识别该确定的表位，这与抗Sm抗体的SLE特异性不同。所鉴定表位的亲和纯化抗体与EB病毒感染的B细胞系中的EBNA1蛋白发生交叉反应。
