Human T-cell Epitopes in SARS

描述(申请人提供)：严重急性呼吸综合征冠状病毒(SARS CoV)来源的人类白细胞抗原限制性细胞毒性T细胞表位和辅助T细胞表位的发现和验证是一个巨大的挑战，因为它的基因组很大，而且由于人类白细胞抗原等位基因的极端多态。在这里，我们建议结合生物信息学方法和高通量MHC-肽结合分析来识别受人类白细胞抗原I类和II类分子限制的表位，这些表位代表了95%的普通人群，而不考虑种族。这些表位将通过体内和体外的免疫原性研究进一步验证，研究使用的是来自健康未暴露供者的人PBMC和HLA转基因小鼠。动物模型可能在SARS特异性疫苗和诊断的发展中发挥重要作用。因此，我们还计划确定小鼠和人MHC分子在人类MHC转基因小鼠中表达的表位。在本应用的最后部分，我们建议探索多表位SARS疫苗构建的发展。该构建体可以单独使用，也可以与其他旨在诱导抗SARS抗体反应的疫苗构建体结合使用。由于建议的方法是基于对SARS衍生多肽序列的免疫原性的系统定义，因此只需要使用最少的活SARS病毒或来自感染或康复中的个人的生物样本。本文建议的研究将导致对一系列表位的定义，促进开发必要的诊断试剂，以严格评估与人类感染相关的T细胞反应，并能够在T细胞免疫水平上评估不同候选疫苗的性能。

DESCRIPTION (provided by applicant): The discovery and validation of HLA-restricted cytotoxic and helper T cell epitopes derived from the Severe Acute Respiratory Syndrome coronavirus (SARS CoV) represents a significant challenge because of the large genome size and because of the extreme polymorphism of HLA alleles. Herein, we propose to combine bioinformatic approaches and high throughput MHC- peptide binding assays to identify epitopes restricted by HLA class I and class II molecules representative of >95% of the general population, irrespective of ethnicity. These epitopes will be further validated with in vivo and in vitro immunogenicity studies utilizing HLA transgenic mice and human PBMC from healthy unexposed donors. Animal models are likely to play a vital role in the development of SARS specific vaccines and diagnostics. Accordingly, we also plan to identify epitopes presented by mouse and human MHC molecules expressed in human MHC transgenic mice. In the final part of this application, we propose to explore development of a multi-epitope SARS vaccine construct. This construct could be utilized by itself, or in conjunction with other vaccine constructs aimed at inducing anti-SARS antibody responses. Because the proposed approach is based on a systematic definition of the immunogenic potential of SARS-derived peptide sequences, only minimal use of live SARS virus or biological samples from infected or convalescent individuals is required. The studies proposed herein will lead to the definition of a broad range of epitopes, facilitate the development of diagnostic reagents necessary to rigorously evaluate T cell responses associated with infection in humans, and enable the evaluation, at the level of T cell immunity, of the performance of different vaccine candidates.