CD8+ T CELL RESPONSE IN RESISTANCE TO TUBERCULOSIS

结核病(TB)是一种慢性传染病，由 胞内细菌病原体结核分枝杆菌。因此，细胞- 介导性免疫而不是抗体是关键的保护性免疫 对结核分枝杆菌的反应。对结核病动物模型的研究表明， 主要组织相容性复合体(MHC)I类限制性CD8 T细胞 反应补充激活的巨噬细胞介导的宿主防御 CD4T细胞，并在成功解决 分枝杆菌感染。然而，在人类中，CD8 T细胞的作用 没有得到充分的解决。我们已经开发出一种体外测试方法， 基于一种新的计算机驱动算法预测MHC I类配体 (多肽)具有被证明的高准确度。我们的化验结果可以测量 通过适当的MHC I类等位基因呈现预测的多肽，因此 允许识别CD8 T细胞识别的表位。 因此，这些研究的总体目标是分析角色 CD8 T细胞应答与结核病耐药性的关系。第一，分泌型分枝杆菌 已知序列的蛋白质将通过计算机程序进行分析 潜在CD8T细胞表位的存在。这些内容的介绍 预测结核分枝杆菌。-由MHC I类衍生的多肽将在 我们对抗原转运蛋白缺陷细胞系的多肽结合试验 表达感兴趣的HLA等位基因。这一分析将扩展到人类白细胞抗原 结核病和艾滋病高发人群中的主要等位基因 感染。第二，这一方法论将用于定量和 MHC-I类限制性CD8 T细胞免疫的定性分析 对结核分枝杆菌的反应PPD健康献血者和结核病患者的衍生肽 病人。外周血中记忆性CD8 T细胞的频率 和细支气管肺泡灌洗液中活化的细胞毒性T淋巴细胞 被测量。肺结核患者CD8T细胞效应功能的比较 与PPD健康捐赠者，以及PPD/HIV感染和活动性结核病/HIV- 感染患者将确定CD8 T细胞之间的相关性 对结核分枝杆菌的反应和耐药性。这些患者中的感染。最后， 结核分枝杆菌。-特异性CD8 T细胞克隆将被分离并具有功能 特色化的。这些T细胞克隆将被用于研究需求 对于MHC I类限制性的结核分枝杆菌。巨噬细胞的抗原 在体外感染活杆菌的。

Tuberculosis (TB) is a chronic infectious disease caused by the intracellular bacterial pathogen Mycobacterium tuberculosis. Hence, cell- mediated immunity rather than antibodies is the critical protective immune response against M. tb. Studies with animal models of TB suggest that the major histocompatibility complex (MHC) class I-restricted CD8+ T-cell response complements host defenses mediated by activated macrophages and CD4+ T cells, and has an important role in successful resolution of mycobacterial infections. However, in humans the role of CD8+ T cells has not been fully addressed. We have developed an in vitro assay that is based on a novel computer-driven algorithm predicting MHC class I ligands (peptides) with a proven high accuracy. Our assay can measure the presentation of predicted peptides by proper MHC class I alleles, and thus allows for identification of the epitopes recognized by CD8+ T cells. Thus, the overall objective of these studies is the analysis of the role of CD8+ T-cell response in resistance to TB. First, secreted mycobacterial proteins with known sequences will be analyzed by the computer program for the presence of potential CD8+ T-cell epitopes. Presentation of these predicted M. tb. -derived peptides by MHC class I will be determined in our peptide-binding assay with an antigen transporter-deficient cell line expressing HLA alleles of interest. This analysis will be extended to HLA alleles predominant in populations with high incidences of TB and HIV infection. Second, this methodology will be used in quantitative and qualitative analysis of the MHC class I-restricted CD8+ T-cell immune responses to M. tb. -derived peptides in PPD+ healthy donors and TB patients. The frequencies of memory CD8+ T cells in the peripheral blood and activated cytotoxic T lymphocytes in the bronchio-alveolar lavage will be measured. Comparison of CD8+ T-cell effector functions in TB patients vs. PPD+ healthy donors, and also in PPD+/HIV-infected and active TB/HIV- infected patients will determine the correlation between the CD8+ T-cell responses and resistance to M. tb. infection in these patients. Finally, M. tb. -specific CD8+ T cell clones will be isolated and functionally characterized. These T cell clones will be used to study the requirements for MHC class I-restricted presentation of M. tb. antigens by macrophages infected in vitro with viable bacilli.