STRUCTURAL FEATURES OF TCR RECOGNITION IN AUATOIMMUNITY

T细胞对人类白细胞抗原/多肽复合体的特异性识别 T细胞受体(TCR)是启动免疫的关键步骤 反应，这种反应是否正常，如在认识到 外来抗原的外来抗原或异常的，如在启动 自身免疫力。TCR赋予免疫反应的特异性 已经使它成为越来越受欢迎的新疗法的目标 旨在专门干扰自身免疫的干预策略 回应。尽管TCR作为可能的目标具有吸引力 治疗方面，关于特定疾病的数据相对较少。 TCRs与形成的络合物相互作用的机理 通过一种人类白细胞抗原分子和一种多肽抗原。大多数的诱变研究 三分子复合体的结构主要集中在多肽上，这些多肽是 在任何位置或在存在的人类白细胞抗原分子上相对容易改变 在许多不同的等位基因形式中，并已进一步被 一些研究中的体外诱变。为了剖析分子 TCR对人类白细胞抗原/多肽复合体的识别，特别是对 定义与HLA-DR相互作用的TCR残基，我们选择 猪瘟病毒免疫优势多肽的DR限制性识别研究 流感病毒血凝素HA 307-319的定点突变 TCR基因及其重新导入合适的受体T细胞 台词。在初步实验中，我们分离到了一些HA 307-319 受各种DR分子限制的特异性T细胞克隆，形成了一种 获得TCR基因突变和再表达的高效体系 抗原特异性激活转基因的TCR，并已开始携带 外链交换和域洗牌实验应该映射到 人类白细胞抗原DR和多肽的一些潜在接触部位的定位 在TCR分子上。在本应用程序中，我们建议在这些基础上 有希望的初步结果如下：(1)扩大我们的HA小组307-319 特定T细胞克隆包括附加DR限制的克隆， (二)系统探索构造重要特征 通过定点突变获得这些克隆的TCR，以及(3) 开发随机诱变TCR基因的体外系统，以及 人类白细胞抗原DR限制性内切酶或抗原改变的新型受体的筛选 专一性。显然有必要对此进行结构性研究 自然在人的模型系统中才能使理性 关于如何设计特定的肽抑制剂的决定，如TCR 拮抗剂，可用于治疗自身免疫性疾病。

The specific recognition of an HLA/peptide complex by a T cell through the T cell receptor (TCR) is a crucial step in initiating an immune response, whether this response is normal, as in the recognition of foreign antigen, or abnormal, as occurs in the initiation of autoimmunity. The specificity conferred on an immune response by the TCR has made it an increasingly popular target for novel therapeutic intervention strategies intended to specifically interrupt autoimmune responses. Despite the appealing nature of TCRs as possible targets for therapy, comparatively little data is available regarding the specific mechanics of the interaction between TCRs and the complex ligand formed by an HLA molecule and a peptide antigen. Most mutagenesis studies of the structure of the trimolecular complex have focused on peptides, which ar relatively easy to alter at any position, or on HLA molecules which exist in numerous different allelic forms and have been further altered by in vitro mutagenesis in some studies. In order to dissect the molecular recognition of HLA/peptide complexes by TCR, and, in particular, to define residues of the TCR that interact with HLA-DR, we have chosen to study the DR restricted recognition of the immunodominant peptide of influenza virus hemagglutinin, HA 307-319, by site directed mutagenesis of TCR genes and their re-introduction into appropriate recipient T cell lines. In preliminary experiments, w have isolated a number of HA 307-319 specific T cell clones restricted by various DR molecules, developed an efficient system for mutagenesis and re-expression.of TCR genes, obtained antigen specific activation of transfected TCRs, and have begun to carry out chain swapping and domain shuffling experiments that should map the location of some potential contact sites for HLA-DR as well as peptide on the TCR molecule. In this application, we propose to build upon these promising preliminary results by (1) expanding our panel of HA 307-319 specific T cell clones to include clones of additional DR restrictions, (2) carry out a systematic probing of the structurally important features of the TCRs from these clones by site directed mutagenesis, and (3) develop an in vitro system for randomly mutagenizing TCR genes, and selecting for novel receptors with altered HLA-DR restriction or antigen specificity. There is a distinct need for structural studies of this nature in human model systems in order to be able to make rational decisions about how to design specific peptide inhibitors, such as TCR antagonists, that could be used therapeutically in autoimmune diseases.