ORIGIN OF ANTI-RO/SSA ANTIBODY

抗 RO/SSA 抗体的来源

• 批准号: 3085652
• 负责人: Robert Hal Scofield
• 金额: $ 7.67万
• 依托单位: OKLAHOMA MEDICAL RESEARCH FOUNDATION
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-03-15 至 1997-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3085652
• 关键词: Sjogren's syndrome; Vesiculovirus; antiantibody; antibody neutralization test; antigen antibody reaction; autoantibody; autoantigens; autoimmune disorder; chemical binding; human tissue; immunopathology; messenger RNA; northern blottings; nucleocapsid; plaque assay; polymerase chain reaction; protein structure; serology /serodiagnosis; southern blotting; systemic lupus erythematosus; virus protein; western blottings

Systemic lupus erythematosus, Sjogren's syndrome, and congenital complete heart block are unified by the presence of autoantibodies binding to Ro/SSA in a variable but substantial proportion (20% to 8O%) of patients with these diagnoses. Ro/SSA is an RNA-protein complex composed of a 60 kD peptide noncovalently bound to one of four small uridine rich RNAs. The sponsor's laboratory is dedicated to understanding the features of this autoantibody-autoantigen system from clinical and autoimmune response relationships to basic structural and antigenic characterization. Overlapping octapeptides have identified a major epitope of 60 kD Ro/SSA which is bound by greater than 50% of anti-Ro/SSA positive SLE patients. This epitope has an unexpected 7 of 8 amino acid sequence identity with the nucleocapsid (N) protein of the vesicular stomatitis virus (VSV). More unexpectedly, RO/SSA and the VSV N protein sequences share a total of six regions of short sequence identity. A reference anti-Ro/SSA serum binds five of the six regions (p=0.001), while 11 additional sera bind four of these six (p=0.003). This is the first known example of possible multiple site molecular mimicry between an autoantigen and a foreign protein. The project is designed to evaluate the fine specificity of the anti-Ro/SSA response and test the hypothesis that this response is immunologically related to VSV N protein. Overlapping peptides of both RO/SSA and VSV N will be prepared. Then the relative binding of anti-Ro/SSA and control sera will be appraised. VSV and related rhabdoviral strains will be used in antibody neutralizing assays and in Western blot assays in an effort to identify the virus most closely related to the anti-Ro/SSA response. Messenger RNA from patients and normal donors will be evaluated for the presence of rhabdovirarl sequences by the polymerase chain reaction and Southern blotting or by the direct evaluation of mRNA in Northern blots. These experiments have the potential to develop independent evidence for the presence of rhabdovirus in patients with anti-Ro/SSA autoantibodies. This project has the potential to at least preliminarily identify a pathogenic stimulus for the anti-Ro/SSA antibody.

系统性红斑狼疮、干燥综合征和先天性 完全性心脏传导阻滞与自身抗体的存在有关 与Ro/SSA的结合比例可变但很大（20%至80%） 有这些诊断的病人。 Ro/SSA是一种RNA-蛋白质复合物 由一个60 kD的肽非共价结合到四个小的 富含尿苷的RNA。 申办方的实验室致力于 了解这种自身抗体-自身抗原系统的特点， 临床和自身免疫反应与基础结构和 抗原特性 重叠的八肽已经确定了一个 60 kD Ro/SSA的主要表位，其被大于50%的 抗Ro/SSA阳性SLE患者。 该表位具有意想不到的7个表位， 8个氨基酸序列的同一性，与核衣壳（N）蛋白的 水泡性口炎病毒（VSV）。 更出乎意料的是，RO/SSA和VSV N个蛋白质序列共有6个短序列区 身份 参考抗Ro/SSA血清结合六个区域中的五个 （p=0.001），而另外11种血清结合这6种中的4种（p=0.003）。 这是已知的第一个可能的多位点分子 自身抗原和外源蛋白之间的模仿。 该项目 设计用于评价抗Ro/SSA应答的精细特异性 并检验这种反应与免疫学相关的假设， VSV N蛋白。 RO/SSA和VSV N两者的重叠肽将是 制备 然后测定抗Ro/SSA和对照血清的相对结合率， 将被评估。 VSV和相关弹状病毒株将用于 抗体中和试验和蛋白质印迹试验， 确定与抗Ro/SSA反应最密切相关的病毒。 将对来自患者和正常供体的信使RNA进行评估，以确定是否存在以下缺陷： 通过聚合酶链反应检测弹状病毒1序列的存在， Southern印迹或通过北方印迹中mRNA的直接评估。 这些实验有可能发展出独立的证据， 抗Ro/SSA自身抗体患者中存在弹状病毒。 该项目有可能至少初步确定一个 抗Ro/SSA抗体的致病性刺激。