Analysis of TCR/HLA/ peptide interaction and investigation of etiology of autoimmune diseases

在以往的研究中，我们发现了特异性HLA II类等位基因与自身免疫性疾病易感性之间的关系，并检测了疾病相关HLA II类分子的结合肽基序。在本研究中，为了阐明特定HLA等位基因与疾病相关的机制，我们进行了以下研究。疾病相关自身反应性T细胞克隆识别的自身肽的鉴定我们从亚洲型多发性硬化（MS）和抗磷脂抗体综合征（APS）患者中建立了许多自身抗原特异性CD 4 ^+ T细胞克隆。我们鉴定了许多来自自身抗原和限制性HLA II类分子的表位，并检测了T细胞克隆产生的细胞因子。此外，我们寻找沃格特-小柳原田病（VKH）的靶自身抗原，VKH是一种自身免疫性疾病，其中炎症性疾病发生在含有黑素细胞的多个器官中。用SEREX法鉴定了透镜上皮细胞（LEDGF ...更多信息 细胞衍生生长因子）和UACA（具有卷曲螺旋结构域和锚蛋白重复序列的葡萄膜自身抗原）作为靶抗原的候选物。2)建立一种识别疾病相关自身反应性T细胞识别的交叉反应性表位的方法。我们建立了一个表达克隆系统来识别CD 4 ^+ T细胞克隆的表位。利用这个系统，我们检测了两个从I型糖尿病患者中建立的特异于谷氨酸脱羧酶65（GAD 65）的CD 4 ^+ T细胞克隆交叉识别的表位模式。基于这些信息，我们确定了微生物抗原来源的几个模拟表位。3)激动性癫痫的类似物诱导的T细胞应答的分析：我们产生了一系列表达HLA-DR 4（DRB 1 ^*0406）和激动剂或部分激动剂肽的复合物的L细胞转染子，这些复合物具有不同的密度。使用转染子，我们发现，当以非常高的密度呈递某些部分激动剂肽时，可以以与完全激动剂肽相似的幅度诱导T细胞应答，并且T细胞应答不伴随ZAP-70和LAT的磷酸化。我们确定了与这种独特的T细胞应答相关的细胞因子产生、TCR下调和细胞内信号传导事件的独特特征。少

In the previous studies, we discovered assedations between specific HLA class II alleles and susceptibility to autoimmune diseases, and examined binding peptide motifs of disease-associated HLA class II molecules. In this study, to clarify the mechanisms of the disease-association of specific HLA alleles, we carried out the following researches. Identification of self peptides recognized by disease-related autoreactive T cell clones. We established many auto-antigen specific CD4^+ T cell clones from Asian type multiple sclerosis (MS) and anti-phosopholipid antibody syndrome (APS) patients. We identified many epitopes derived from self antigens and restricting HLA class II molecules, and examined the cytokines produced by the T cell clones. In addition, we searched for the target autoantigen of Vogt -Koyanagi-Harada disease (VKH), an autoimmune diseas e in which inflammatory disorders occur in multiple organs containing melanocytes. By SEREX method, we identified LEDGF (Lens Epithelial … More Cel l Derived Growth Factor) and UACA (Uveal Autoantigen with Coiled coil domains and Ankyrin repeats) as candidates for the target antigen. 2) Establishment of a method to identify cross-reactive epitopes recognized by disease-related autoreactive T cells.We established an expression cloning system to identify epitopes for CD4^+ T cell clones. Using this system, we examined the pattern of epitopes cross-recognized by two CD4^+ T cell clones established from Type I diabetes patients and specific to glutamate decarboxylase 65 (GAD65). Based on this information, we identified several mimicry epitopes of microbial antigen origin. 3) Analysis of T cell response induced by analogues of agonistic epilopes.We generated series of L cell transfectants expressing complexes of HLA-DR4 (DRB1^*0406) and agonist or partial agonist peptides in various densities. Using the transfectants, we discovered that a certain partial agonist peptide, when presented in a very high density, can induce T cell response in a similar magnitude as a full agonist peptide, andthat the T cell response is not accompanied by phosphorylation of ZAP-70 and LAT. We identified unique profiles of produced cytokines, down-modulation of TCR, and intracellular signaling events associated with this unique T cell response. Less