结核及耐药结核感染中CD244的免疫功能与机制

Elucidation of immune regulation mechanisms in tuberculosis (TB) infection is one of fundamental works to develop novel TB vaccines, diagnostic and therapeutic technologies. We (PNAS, 2015) have recently demonstrated that active TB infection in humans induced up-regulation of CD244 on CD8+T effectors, which significantly inhibited the effector functions of CD8+T effectors. However, since the T cell effector functions may mediate either protective immunity or detrimental immunopathology in TB, it remains unclear whether and how CD244-inhibited effector functions of CD8+T cells may determine the TB infection outcomes. Thus, we will continuously develop following strategies to address the exact role of CD244 signaling in determining the TB infection outcomes: (i) Mice will be first infected with TB and drug-resistant TB, and used anti-CD244 mAb to block the CD244 signaling in presence or absence of CD4+T cells deletion; (ii) CD8+T effectors will be treated with anti-CD244 blockade Ab to block the CD244 signaling in CD8+T cells, and then these CD8+T cells with or without CD244 blockade will be adoptive transferred to TB-infected mice. We will then fully evaluate the TB bacillus burdens and TB pathology as well as immunological responses of T cells in mice. We will also analyze the correlation between CD244 expression on CD8+T cells and development, progress, and prognosis of human TB infection. The current project will provide the first line of evidence demonstrating the exact role of CD244 signaling in determining TB infection outcomes, and therefore will serve as critical basis for development of CD244-based novel TB prevention and treatment methods.

阐明结核的免疫调控机制是开发新的结核疫苗、诊断及治疗技术从而遏制结核严峻疫情的关键基础。我们（PNAS，2015）最近证明结核感染诱导CD244在CD8+ T效应细胞中显著上调表达并抑制CD8+ T细胞的效应功能。但是，我们的前期工作及同行也证明T细胞效应功能对控制结核感染的结局具有保护性或病理性双重影响，所以CD244介导的CD8+ T细胞免疫抑制究竟如何决定结核感染的结局仍不清楚。为此，项目拟在前期工作及预实验基础上，继续在结核及耐药结核感染的小鼠中，去或不去除CD4+ T细胞并阻断CD244，或者阻断CD8+ T细胞的CD244并将其过继转移至结核感染的小鼠，从而系统阐述CD244是否并如何影响小鼠的免疫功能、结核负担与病理病变；同时，将分析CD244的表达与结核病情发展与转归的临床相关性。项目将率先准确定义CD244的免疫保护或病理功能及其机制，从而为结核的防治提供新技术、新思路。

项目团队紧紧围绕“结核及耐药结核感染中CD244的功能与机制”这个关键科学问题开展研究工作。主要的研究内容包括：（1）研究CD244相关的抗结核免疫T细胞如何随着活动性结核病人抗结核治疗进程而变化。（2）研究开发一类以纳米硒为基础的、增强了抗结核药物的巨噬细胞靶向性、有效调动CD244相关免疫细胞的抗结核保护功能的抗结核系统。（3）研究并构建能够靶向巨噬细胞及CD244相关免疫细胞的氧化石墨烯系统，并用于抗结核药物利福平的靶向递送。重要成果：（1）阐明了CD244相关的抗结核免疫T细胞如何随着结核病程发生发展、抗结核治疗前后而变化，证明Th1/CD8+ 效应T细胞水平的恢复是结核病预后及转归的关键参考指标，从而为结核及耐药结核感染的免疫治疗提供坚实的理论指导与方法支撑。（2）基于CD244在抗结核免疫治疗中的功能，项目团队依靠跨学科平台，率先构建了以纳米硒为基础的新型抗结核药物靶向递送系统，增强了抗结核药物的巨噬细胞靶向性，有效调动CD244相关免疫细胞的抗结核保护功能，从而为提高抗结核药物疗效提供了新策略。（3）设计并构建了具有巨噬细胞及CD244相关免疫细胞靶向能力的氧化石墨烯系统，成功用于抗结核药物利福平的靶向递送，更高效的杀灭胞内结核分枝杆菌，从而为解决抗结核药物的治疗难题提供新思路。本项目开展的研究和取得的成果为更好的阐明“结核及耐药结核感染中CD244的功能与机制”提供了新思路，为更有效的解决结核病预防与治疗提供了新策略。项目相关成果以通讯作者发表在著名期刊《Angewandte Chemie International Edition》等期刊上，并申报了2项发明专利。