Inhibition of Antigen Presentation in Multiple Sclerosis

描述（由申请人提供）：本项目的长期目标是开发用于治疗多发性硬化（MS）的抗原呈递小分子抑制剂。MHC II类分子被认为通过将髓鞘抗原的肽呈递给CD 4 T细胞在疾病过程中起关键作用。全基因组研究已经证明与MHC II类区域的连锁，并且HLA-DR 2单倍型（DRB 1 *1501）与家族性和散发性病例中的疾病易感性相关。研究人员先前已经确定了HLA-DR 2（HLA-DR 2，DRB 1 *1501）的晶体结构，这表明了代表特异性抑制剂潜在靶点的结合位点的特征。在DM或不变链缺陷小鼠中的研究已经证明，CNS中的抗原呈递是CNS炎症发展的严格要求。该项目的主要假设是，阻断髓磷脂抗原呈递给CD 4 T细胞的关键步骤的小分子可以防止MS病变的发展。该项目将与最近成立的哈佛神经变性和修复中心（HCNR）密切合作，该中心正在开发针对神经系统疾病的药物发现计划。该中心的目标，以及这个特定项目的目标，是根据正在进行的研究工作开发治疗方法，并在相关动物模型中测试化合物。抑制剂的鉴定将集中在抗原呈递细胞中肽加载到MHC II类分子上的机制上。特别相关的是DM催化的恒定链衍生的CLIP肽的解离，因为它先于抗原肽与MHC II类分子的结合。研究人员开发了一种哺乳动物表达系统，该系统提供了适量的HLA-DR 2/CLIP复合物，用于分析大型和多样化的小分子文库。初步研究表明，荧光偏振提供了一个敏感的，实时读出肽结合这些HLA-DR 2/CLIP复合物。该项目的具体目标是：开发用于鉴定阻断髓鞘肽呈递的小分子的测定法（目标1），在与细胞内肽负载相关的条件下检查大量不同的小分子集合（目标2），并研究化合物抑制髓鞘抗原呈递的机制（目标3）。

DESCRIPTION (provided by applicant): The long-term objective of this project is to develop small molecule inhibitors of antigen presentation for the treatment of multiple sclerosis (MS). MHC class II molecules are thought to play a critical role in the disease process by presenting peptides from myelin antigens to CD4 T cells. Genome-wide studies have demonstrated linkage to the MHC class II region, and the HLA-DR2 haplotype (DRB1*1501) is associated with disease susceptibility in both familial and sporadic cases. The investigator has previously determined the crystal structure of HLA-DR2 (DRA, DRB1*1501), which demonstrates features of the binding site that represent potential targets for specific inhibitors. Studies in mice deficient in DM or invariant chain have demonstrated that antigen presentation in the CNS is strictly required for the development of CNS inflammation. The major hypothesis of this project is that small molecules which block critical steps in the presentation of myelin antigens to CD4 T cells can prevent the development of MS lesions. The project will be performed in close collaboration with the recently established Harvard Center for Neurodegeneration and Repair (HCNR) that is developing a drug discovery program directed at neurological diseases. The goal of the center, and of this particular project, is to develop therapeutic approaches based on ongoing research efforts, and to test compounds in relevant animal models. The identification of inhibitors will focus on the mechanisms of peptide loading onto MHC class II molecules in antigen presenting cells. Particularly relevant is the DM catalyzed dissociation of the invariant chain derived CLIP peptide since it precedes binding of antigenic peptides to MHC class II molecules. The investigator has developed a mammalian expression system that provides suitable quantities of the HLA-DR2/CLIP complex for analysis of large and diverse libraries of small molecules. Preliminary studies demonstrate that fluorescence polarization provides a sensitive, real-time readout of peptide binding to these HLA-DR2/CLIP complexes. The specific aims of the project are: To develop assays for the identification of small molecules that block presentation of myelin peptides (Aim 1), to examine a large and diverse collection of small molecules under conditions relevant for intracellular peptide loading (Aim 2), and to study the mechanisms by which compounds inhibit presentation of myelin antigens (Aim 3).