CD8+ T CELL RESPONSE IN RESISTANCE TO TUBERCULOSIS

结核病（TB）是一种由结核病引起的慢性传染病 细胞内细菌病原体结核分枝杆菌。因此，细胞- 介导的免疫而不是抗体是关键的保护性免疫 针对 M. tb 的回应。结核病动物模型研究表明 主要组织相容性复合体 (MHC) I 类限制性 CD8 T 细胞 反应补充了由活化的巨噬细胞介导的宿主防御 CD4 T 细胞，在成功解决问题中具有重要作用 分枝杆菌感染。然而，CD8 T 细胞在人类中的作用 没有得到充分解决。我们开发了一种体外检测方法 基于预测 MHC I 类配体的新型计算机驱动算法 （肽）具有经过验证的高精度。我们的测定可以测量 通过适当的 MHC I 类等位基因呈现预测的肽，因此 允许鉴定 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 细胞在抵抗结核病中的反应。一、分泌型分枝杆菌 具有已知序列的蛋白质将通过计算机程序进行分析 潜在的 CD8 T 细胞表位的存在。这些的介绍 预测 M. tb。 -MHC I 类衍生肽将在 我们使用抗原转运蛋白缺陷细胞系进行肽结合测定 表达感兴趣的 HLA 等位基因。该分析将扩展到 HLA 等位基因在结核病和艾滋病毒高发人群中占主导地位 感染。其次，该方法将用于定量和 MHC I 类限制性 CD8 T 细胞免疫的定性分析 对 M. tb 的回应。 - PPD 健康供体和结核病中的衍生肽 患者。外周血中记忆CD8 T细胞的频率 支气管肺泡灌洗液中活化的细胞毒性 T 淋巴细胞将 被测量。结核病患者CD8 T细胞效应功能比较 与 PPD 健康捐赠者相比，以及 PPD/HIV 感染者和活动性 TB/HIV 捐赠者 感染患者将确定 CD8 T 细胞之间的相关性 对 M. tb 的反应和抵抗力。这些患者的感染。最后， M.tb。 - 特异性 CD8 T 细胞克隆将被分离并具有功能 特点。这些T细胞克隆将用于研究需求 M. tb 的 MHC I 类限制性表达。巨噬细胞抗原 体外用活杆菌感染。

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.