HLA-D antigens, T cell epitopes and antibody specificity in SLE

描述(由申请人提供)： 在目前的SCOR期间，在阐明狼疮自身抗体多样化的机制和识别与SLE相关自身抗原反应的重要的HLA-D限制性元件方面取得了重大进展。交叉反应性自身抗体和对一个或多个SLE相关自身抗原反应的抗原特异性T细胞的扩增在自身抗体反应的多样化中是重要的。在目前可用的表达D区分子的转基因小鼠中，DR2和DR3是控制重组ROM的沉淀抗体应答和分子间表位扩散到Ro52的主要决定因素。在SMD免疫中，随着SMB特异性抗体的产生，DR3被证明是主要的。这一竞争性更新应用是为了继续探讨SLE相关自身抗原中的人类白细胞抗原-D区和T细胞表位在SLE发病机制中的作用。具体目标1：利用已有的转基因小鼠进一步定位Ro60、SMD、SMB上的T细胞表位和A蛋白 SnRNP颗粒，通过产生抗原特异性TT杂交瘤。特异性目的2：通过负载SLE相关抗原肽的HLA-DR四聚体研究SLE患者和对照组的抗原性T细胞。这是弗吉尼亚大学和弗吉尼亚·梅森研究中心的合作项目。特异性目的3：构建缺失小鼠完整I区基因的NZM2328突变体，并以转基因的形式表达不同的人类白细胞抗原-D区分子，以确定这些转基因基因是否支持自身抗体的自发产生和急、慢性肾小球肾炎的诱导。他们还将接受测试，以确定CMV是否会诱发慢性涎腺炎。具体目标4：启动一项合作研究，比较印度北部和弗吉尼亚州中部SLE人群中抗Sm抗体的特异性。患者和匹配的正常对照都将进行人类白细胞抗原分型，并将进行目标2中概述的研究。这些实验结果将为进一步探讨分子拟态在SLE发病机制中的重要性提供依据。这也可能为自身抗体的多样化和这种疾病中终末器官损害的产生提供新的见解。

DESCRIPTION (provided by applicant): During the current SCOR period, significant progress has been made to elucidate the mechanism of lupus autoantibody diversification and to identify important HLA-D restriction elements in response to SLE-related autoantigens. Crossreactive autoantibodies and the expansion of antigen-specific T cells reactive to one or more SLE-related autoantigens are important in the diversification of autoantibody response. With current available transgenic mice expressing D region molecules, DR2 and DR3 are the dominant determinants controlling the magnitude of the precipitating antibody response to recombinant ROM and for intermolecular epitope spreading to Ro52. For SmD immunization, DR3 was shown to be dominant with the generation of specific antibodies for SmB. This competitive renewal application is to continue to explore the role of HLA-D region and T cell epitopes in SLE-related autoantigens in the pathogenesis of SLE. Four specific aims are proposed: Specific Aim 1: To use the existing transgenic HLA-DR3 and -DR4 mouse to map further the T cell epitopes on Ro60, SmD, SmB and the A protein of the snRNP particle, by generation of antigen-specific TT hybridomas. Specific Aim 2: To study antigenspecific T cells by HLA-DR3 and HLA-DR4 SLE patients and matched controls by HLA-DR tetramers loaded with SLE-related antigenic peptides. This is a collaboration between UVa and Virginia Mason Research Center. Specific Aim 3: To generate NZM2328 mutants which lack the entire mouse I region and express the various HLA-D region molecules as transgenes to determine whether these transgenes can support the spontaneous autoantibody generation and the induction of acute and chronic glomerulonephritis. They will also be tested to determine whether chronic sialoadenitis can be induced by CMV. Specific Aim 4: To initiate a collaborative study to compare the antiSm antibody specificity in the SLE populations of northern India and central Virginia. Both patients and matched normal controls will be HLA- typed and studies as outlined in Aim 2 will be performed. The results obtained in these experiments will provide a basis for further exploration of the importance of the molecular mimicry in the pathogenesis of SLE. It might also provide newer insight into autoantibody diversification and the generation of end-organ damage in this disease.