肿瘤坏死因子-α（TNF-α）对单核/巨噬细胞分化的调控： 抗TNF-α治疗增加类风湿关节炎患者结核感染风险的免疫学机制

Over-expression of tumor necrosis factor-α (TNF-α) promotes the inflammatory injury in rheumatoid arthritis. Although anti-TNF therapy have been proved to improves RA, the risk of tuberculosis increased with anti-TNF therapy. Monocytes/macrophages involve in anti-pathogen infection, and its differentiation and function determine the progress and outcome of infection. It was demonstrated that TNF-α play a vital role in differentiation of monocytes/macrophages. We previously found that loss of TNF led to resistant mice succumb to cutaneous Leishmania with developing a novel M2 macrophage population. In present study, we are going to infect B6.TNF-/- mice and peripheral blood mononuclear cells (PBMCs) with tuberculosis. We are going to use confocal microscopy, flow cytometry, and gene array to determine the if TNF affect the phenotype and function of monocytes/macrophages during infection. The results will illustrate the differentiation of M2 macrophages involve in the pharmacological mechanism of increased risk of tuberculosis with anti-TNF therapy, and potentially provide the evidence that M2 macrophages play as an immune biomarker and indicator for the risk of tuberculosis when patients with anti-TNF therapy.

抗肿瘤坏死因子（TNF）治疗缓解类风湿关节炎（RA）的病程进展，但增加患者结核感染的风险，且机制未明。单核／巨噬细胞在感染免疫中十分重要，其分化、表型和功能决定感染的表现和转归，而TNF是调节巨噬细胞分化的关键因子。课题组前期发现，TNF缺失导致利什曼原虫感染小鼠的单核／巨噬细胞异常分化为M2型巨噬细胞，加剧并导致小鼠的感染和死亡。本项目拟用TNF基因敲除小鼠和接受抗TNF治疗的RA患者外周血单个核细胞建立结核感染模型，通过流式细胞术、激光共聚焦和基因芯片等技术，研究TNF的缺失对小鼠结核感染的影响和单核／巨噬细胞分化及功能的调控、抗TNF治疗RA患者单核／巨噬细胞感染结核后表型和功能变化，以及相关NF-κB信号通路传导的变化。从而揭示M2型巨噬细胞异常分化参与抗TNF治疗增加结核感染风险的免疫学机制，为利用M2型巨噬细胞作为抗TNF治疗时监测结核感染的免疫标志物提供实验依据。

抗肿瘤坏死因子（TNF）治疗增加结核感染肺损伤的风险，但机制未明。本项目使用TNF敲除基因鼠和接受抗TNF治疗的患者外周血样本为对象，研究TNF缺失对结核杆菌在肺巨噬细胞中感染的变化和机制。研究发现，TNF缺失加剧小鼠结核感染的死亡率和肺损伤，促进单核/巨噬细胞的异常表型和功能变化。体外培养小鼠骨髓源单核细胞，TNF干扰后能显著提高抗炎型巨噬细胞的比例，促进Mtb在细胞内的存活。使用临床样本研究发现，接受抗TNF治疗的RA患者单核/巨噬细胞表型和功能变化，对结核易感性增高，促进Mtb在细胞内的存活。本项目的工作为为明确抗TNF治疗导致结核感染诱导肺损伤的机制提供实验证据。为动态监测巨噬细胞的异常表型，避免抗TNF-α治疗不良反应提供依据。