HUMAN CARTILAGE GP39 IN HLA-DR4 TRANSGENIC MURINE MODEL

类风湿关节炎(RA)被认为是一种自身免疫性疾病，在这种疾病中，T细胞错误地攻击透明软骨基质蛋白，如II型胶原。在与RA相关的自身抗原中，一种新的候选靶抗原-人软骨GP-39(HC-GP-39)已被描述。确定自身免疫反应的参数可能有助于诊断和制定新的治疗策略。例如，如果已知HC GP-39决定簇(S)或在人类MHC等位基因背景下识别的其他软骨抗原，就可以设计特定的免疫干预策略，从而特异性地干扰自身免疫反应。在大多数情况下，对类风湿性关节炎和多发性硬化症(MS)等T细胞介导的自身免疫性疾病患者的决定簇图谱研究未能提供明确的结果，而且到目前为止，对近交系小鼠的研究通常集中在小鼠MHC单倍型的决定簇利用上，因此可能不适用于人类。我建议在本申请中描述的实验中克服这一限制，使用已被设计为表达人类MHC II类等位基因的小鼠，包括RA易感等位基因HL A-DR4(HL A-DRB1 0401)和HL A-DRW 14(HL A-DRB1 0404)，从而创建具有人源化抗原呈递特性的小鼠免疫系统。我们的实验将验证T细胞对人类II型胶原和HC GP-39表位的识别在人类白细胞抗原DR4和人类白细胞抗原14转基因小鼠多发性关节炎的诱导和/或增殖中的重要性，以及T细胞反应的分子内和分子间传播是否在多发性关节炎的增殖中具有重要意义。根据这些信息，我们将能够监测患者的反应，并为特定的免疫干预设计策略。这一基本信息不能通过测试传统的小鼠品系获得，也不能通过人类研究获得，但它可以很容易地通过使用本研究中提出的人源化小鼠来获得。

Rheumatoid arthritis (RA) is thought to be an autoimmune disease in which T cells erroneously attack hyaline cartilage matrix proteins like, for example type II collagen. Amongst the autoantigens implicated in RA, a novel candidate target antigen, human cartilage gp-39 (HC-gp-39) has been described. Defining the parameters of the autoimmune response may facilitate diagnosis and formulation of novel therapeutic strategies. For example, if the determinant(s) of HC gp-39 or other cartilage antigens recognized in the context of human MHC alleles were known, specific strategies for immune intervention could be designed which would interfere specifically with the autoimmune response. For the most part, determinant mapping studies of patients with T cell-mediated autoimmune diseases like RA and Multiple Sclerosis (MS) have failed to provide clear results and studies on inbred mouse strains have so far usually focused on determinant utilization in the context of murine MHC haplotypes and so may not pertain to humans. I propose to overcome this limitation for the experiments described in this application by using mice that have been engineered to express human MHC class II alleles including the RA susceptibility alleles HLA-DR4 (HLA-DRB1 0401) and HLA-DRW 14 (HLA-DRB1 0404), which will thus create a murine immune system with humanized antigen presentation properties. Our experiments will test the hypothesis that T cell recognition of human collagen type II and HC gp-39 epitopes are of importance in induction and/or propagation of polyarthritis in HLA-DR4 and HLA-DR14 transgenic mice, and whether intra-and intermolecular spreading of T cell responses are of significance in the propagation of polyarthritis. Based on this information, we will then be in a position to monitor responses in patients and design strategies for specific immune intervention. This essential information cannot be obtained by testing conventional mouse strains, nor through human studies, but it can readily be obtained through the use of humanized mice as proposed in this study.