Jo-1-specific T Cell Responses in Polymyositis

描述(由申请人提供)： 多发性肌炎是一种自身免疫性疾病，肌肉不适当地被T细胞介导的破坏作为靶点。由于抗原触发因素(S)仍不清楚，目前的治疗方法是非特异性的，依赖于全球免疫抑制。多发性肌炎存在不同的临床亚群，由针对特定核抗原和细胞质抗原的抗体定义，包括Jo-1(组氨酰-tRNA合成酶)。基于一系列的遗传学、血清学和组织形态学数据，该建议的基本假设是针对Jo-1的抗原特异性T细胞反应促进抗Jo-1抗体的形成以及T细胞介导的细胞溶解/功能障碍在Jo-1+多发性肌炎中的肌肉细胞。，这项研究的初始阶段将确定体外T细胞增殖和细胞因子对Jo-1的反应。随后的实验将涉及从Jo-1+多发性肌炎患者和健康对照组的外周血中克隆Jo-1特异性T细胞。然后，使用Jo-1片段和线性多肽进行TCR测序和表位映射研究，将允许进一步表征Jo-1特异性T细胞谱系，并便于比较来自多发性肌炎患者和健康对照组的Jo-1特异性T细胞。这些Jo-1特异性T细胞亚群在体内病变肌肉的淋巴细胞浸润液中的定位将通过RT-PCR和免疫组织化学技术进行研究。肌肉浸润性淋巴细胞的克隆将提供一个抗原特异性细胞池，用于分析对Jo-1以及其他从肌肉蛋白提取物中提取的假定自身抗原的反应。将Jo-1特异性T细胞应用于体外培养的自体肌管后，对心肌细胞破坏的评估将进一步确定这种T细胞在Jo-1+多发性肌炎中的作用。这些研究也旨在提供关于改变的T细胞谱系和抗原提呈在Jo-1+多发性肌炎表达中的相对作用的洞察力。

DESCRIPTION (provided by applicant): Polymyositis represents an autoimmune disease in which muscle is inappropriately targeted for T cell-mediated destruction. Because the antigenic trigger(s) remain unknown, current therapies are non-specific and rely on global immunosuppression. Distinct clinical subsets of polymyositis exist that are defined by antibodies directed against specific nuclear and cytoplasmic antigens including Jo-1 (histidyl-tRNA synthetase). Based on a range of genetic, serologic, and histomorphologic data, the underlying hypothesis of this proposal is that antigen-specific T cell responses directed against Jo-1 promote anti-Jo-1 antibody formation as well as T cell-mediated cytolysis/dysfunction of muscle cells in Jo-1+ polymyositis. , The initial phase of this study will define the in vitro T cell proliferative and cytokine responses to Jo-1. Subsequent experiments will involve cloning of Jo-1-specific T cells derived from the peripheral blood of patients with Jo-1 + polymyositis and healthy controls. TCR sequencing as well as epitope mapping studies using both Jo-1 fragments and linear peptides will then permit further characterization of the Jo-1-specific T cell repertoire and facilitate comparison of Jo-1-specific T cells derived from polymyositis patients and healthy controls. Localization of these Jo-1-specific T cell subsets to lymphocytic infiltrates of diseased muscle in vivo will be investigated through RT-PCR and immunohistochemistry techniques. Cloning of muscle-infiltrating lymphocytes will provide a pool of antigen-specific cells to be analyzed for responses to Jo-1 as well as other putative autoantigens derived from muscle protein extracts. Assessment of myocyte destruction after the application of Jo-1-specific T ceils to autologous myotube cultures in vitro will further define the role of such T cells in Jo-1+ polymyositis. These studies are intended to also provide insight concerning the relative roles of altered T cell repertoire and antigen presentation in the expression of Jo-1+ polymyositis.