ANTIBODIES THAT PLAY DIFFERENT ROLES IN MYASTHENIA GRAVI

这项研究计划涉及自身抗体的表征 对乙酰胆碱的肌肉受体（AChR）具有反应性 导致神经肌肉疾病，重症肌无力（MG）。 过去 观察结果表明， MG患者产生的循环抗AChR抗体及其严重程度 导致的疾病症状。因此，这一目标 调查是为了证明个别物种之间的区别 个体患者产生的抗AChR抗体， 将抗体分类为与1） 抗原结合精细特异性的特定模式（包括 与主要免疫原性区域（MIR）的反应性和有趣的免疫原性区域（MIR）的反应性。 在过去注意到的交叉反应性（即，AChR和肌球蛋白之间]），以及 2)具有或高或低的致病潜力。 将采用的战略 是将抗原结合精细特异性的联合收割机测定与 基于抗体等电点的抗体分析和纯化 (i.e.,制备等电聚焦）。通过这种方式， 在与AChR的特定反应模式之间， “克隆型”B细胞产物（即，抗AChR抗体）。这应该 允许从不同的角度看待这种关系， 未分级MG血清中发现的多克隆抗体的研究。 因此，该项目将根据若干方面的具体目标， 患者抗体结合和纯化的标准如下所述。 此外，将在特定子集之间寻找关系 抗体及其结合特异性， 影响AChR的表达及其致病潜力。 具体目标1.确定反应性特征和潜力 免疫病理学关系涉及抗- 乙酰胆碱受体抗体。分析IEF将用于评估反应性， 抗AChR抗体相对于MIR的交叉反应性概况- 相关肽和肌球蛋白，以及与11 E10的关联 独特型 将使用纯化IEF（pIEF）进行克隆型纯化 用于结合特异性试验的限制性抗AChR抗体， 受体交联/下调活性，以及 通过被动抗体转移研究， 免疫幼稚大鼠。 具体目标2.确定血清学和潜在免疫病理学 涉及抗AChR抗体的克隆型物种与 对MR相关合成肽的特异性。抗体是 已通过吸附和洗脱进行亲和纯化的 从Sepharose柱，其中α 61 -76 MIR相关肽具有 被附。这些抗原特异性抗体的评价将在 类似于具体目标1所述的那些。 具体目标3.确定血清学和潜在免疫病理学 涉及抗AChR抗体的克隆型物种的关系， 缺乏对MIR-associated合成肽特异性。为了 进一步阐明血清学和免疫病理学的重要性， 对MIR具有反应性的抗体，患者IG已耗尽 与α 61 -76 MIR相关肽的反应性将是 考察这些抗原特异性抗体的评价将在 类似于具体目标1所述的那些。

This research proposal involves the characterization of autoantibodies with reactivity for the muscle receptor for acetylcholine (AChR) responsible for the neuromuscular disorder, myasthenia gravis (MG). Past observations indicate a frequent disparity between the level of circulating anti-AChR antibodies produced in MG patients and the severity of resulting disease symptoms. Therefore, the objective of this investigation is to demonstrate distinctions among the individual species of anti-AChR antibodies produced by individual patients that might allow the categorization of antibodies into subsets associated with 1) particular patterns of antigen binding fine-specificity (including reactivity with the main immunogenic region (MIR) and the intriguing crossreactivities noted in the past (i.e., between AChR and myosin]), and 2) with high or low disease-causing potential. The strategy to be used is to combine determinations of antigen binding fine-specificity with the analysis and purification of antibodies based on their isoelectric point (i.e., preparative isoelectric focusing). In this way, relationships may be revealed between particular patterns of reactivity with the AChR and "clonotypic" B cell products (i.e., anti-AChR antibodies). This should allow a different perspective on such relationships than have past studies of the polyclonal antibodies found in unfractionated MG sera. Accordingly, this project will address specific aims based on several criteria of patient antibody binding and purification described below. Additionally, relationships will be sought between particular sub sets of anti body and their binding specificity, with their ability to influence the expression of AChR and their disease-causing potential. SPECIFIC AIM 1. Determine the reactivity profile and potential immunopathological relationships involving -clonotypic species of anti- AChR antibodies. Analytical IEF will be used to assess the reactivity and crossreactivity profiles of anti-AChR antibodies with respect to the MIR- associated peptide and myosin, as well as for associations with the 11E10 idiotype. Preparative IEF (pIEF) will be used to purify clonotypically restricted anti-AChR antibodies for tests of binding specificity, receptor crosslinking/down-modulating activities, and for tests of disease-causing potential via passive antibody transfer studies into immunologically naive rats. SPECIFIC AIM 2. Determine serological and potential immunopathological relationships involving clonotypic species of anti-AChR antibodies with specificity for an MlR-associated synthetic peptide. Antibodies are to be studied that have been affinity-purified by adsorption to and elution from Sepharose columns to which the alpha61-76 MlR-associated peptide has been attached. Evaluations of these antigen-specific antibodies will be similar to those described for Specific Aim 1. SPECIFIC AIM 3. Determine serological and potential immunopathological relationships involving clonotypic species of anti-AChR antibodies that lack specificity for an MIR-associated synthetic peptide. In order to further clarify the serological and immunopathological importance of antibodies with reactivity to the MIR, patient Ig that has been depleted of reactivity with the alpha61-76 MlR-associated peptide will be examined. Evaluations of these antigen-specific antibodies will be similar to those described for Specific Aim 1.