NOVEL MHC CLASS II CONSTRUCTS FOR TREATMENT OF EAE

MHC/肽-抗原复合物与T细胞受体（TCR）之间的相互作用对于抗原特异性T细胞活化是必需的。 抗原类似物可以作为T细胞活化的强大和特异性抑制剂，并为过敏和自身免疫性疾病的抗原特异性免疫干预提供了合理的方法。 用髓鞘碱性蛋白（MBP）或MBP肽免疫的刘易斯大鼠发生实验性自身免疫性脑脊髓炎（EAE），这是一种CD 4+、Th 1细胞介导的中枢神经系统（CNS）脱髓鞘疾病，用作人类疾病多发性硬化症（MS）的模型。 在EAE的刘易斯大鼠模型中，对MBP-72-89特异的T细胞主导自身免疫应答，并且病原性T细胞上的TCR表达被充分表征。 该模型提供了一个极好的机会来检验调节MHC/肽与TCR相互作用的背景可以用于控制抗原指导的T细胞活化的假设。 我们最近开发了一个新的分子家族，来自大鼠MHC II类α-1和β-1结构域，有和没有遗传连接的多肽表位。 非共价和共价beta1 α 1/MBP-72-89构建体均抑制致病性MBP-72-89反应性T细胞的活化，并可用于预防和治疗EAE。 这些分子在治疗人类自身免疫性疾病中的潜力为进一步表征这些分子调节CD 4+致病性T细胞的机制提供了强有力的理论基础。 我们建议1）对β 1 α 1分子进行生物化学表征; 2）通过直接结合研究确定TCR和β 1 α 1/肽分子之间的相互作用表面来确定β 1 α 1/肽分子的特异性; 3）表征β 1 α 1/肽分子的体外作用，并定义β 1 α 1/肽分子在体外作用的时间范围和背景。肽处理可以改变效应细胞对抗原刺激的响应的活化;和4）表征β 1 α 1/肽分子的体内作用，目的是确定β 1 α 1/肽分子阻断体内EAE诱导的机制。

The interaction between the MHC/peptide-antigen complex and the T cell receptor (TCR) is essential for antigen-specific T cell activation. Antigen analogs can act as powerful and specific inhibitors of T cell activation and provide a rational approach to antigen-specific immuno-intervention in allergies and autoimmune diseases. Lewis rats immunized with myelin basic protein (MBP) or MBP peptides develop experimental autoimmune encephalomyelitis (EAE), a CD4+, Th1 cell-mediated demyelinating disease of the central nervous system (CNS) that is used as a model for the human disease multiple sclerosis (MS). In the Lewis rat model of EAE, T cells specific for MBP-72-89 dominate the autoimmune response and TCR expression on the pathogenic T cells is well characterized. This model provides an excellent opportunity to test the hypothesis that regulating the context in which MHC/peptide interacts with TCR can be used to control antigen-directed T cell activation. We have recently developed a family of novel molecules derived from the rat MHC class II alpha-1 and beta-1 domains, with and without a genetically linked polypeptide epitope. Both the non-covalent and covalent beta1alpha1/MBP-72-89 constructs inhibited activation of pathogenic MBP-72-89 reactive T cells and could be used to prevent and treat EAE. The potential of these molecules in the treatment of human autoimmune disease provides a strong rationale to further characterize the mechanism by which these molecules regulate CD4+ pathogenic T cells. We propose to 1) Characterize the beta1alpha1 molecules biochemically; 2) Determine the specificity of the beta1alpha1/peptide molecules by direct binding studies to define the interaction surface between the TCR and beta1alpha1/peptide molecules; 3) To characterize the in vitro effects of the beta1alpha1/peptide molecules and define the time-frame and context within which beta1alpha1/peptide treatment can alter the activation of effector cells in response to antigen stimulation; and 4) To characterize the in vivo effects of the beta1alpha1/peptide molecules, with the goal of defining the mechanism by which the beta1alpha1/peptide molecules block the induction of EAE in vivo.