【摘要】 目的观察耐药结核分枝杆菌(mycobacterium tuberculosis,MTB)的耐药特性是否与其使细胞毒性T细胞(CD8+T lymphocytes,CTL)活性受损而不能诱导巨噬细胞凋亡有关。方法先用密度梯度离心法分离出各受试人群的外周血单个核细胞,再进一步分离出巨噬细胞和CD8+T淋巴细胞。以自身MTB-Ag刺激巨噬细胞后,再与自身CD8+T淋巴细胞混合培养,以形成特异杀伤MTB的CTLs用ELISA法检测CTL分泌穿孔素、颗粒酶B、颗粒溶素的情况以及巨噬细胞上TLR2水平,再用化学发光法检测巨噬细胞上Caspase-3水平并与非耐药肺结核患者及健康人群进行比较。结果耐药肺结核患者CTL经自身MTB-Ag刺激后,穿孔素、颗粒酶B、颗粒溶素的分泌水平远低于非耐药结核患者,甚至低于健康人群。耐药肺结核患者Mac上TLR2及细胞的Caspase-3水平也显著低于非耐药结核患者。结论 CTL的细胞免疫功能受损可能是耐药MTB-Ag对宿主机体的一种免疫逃避机制,从而维持其在宿主体内的持续感染状态。更多还原

【Abstract】 Objective To investigate whether the drug resistance of mycobacterium tuberculosis(MTB)is related to the impaired cytotoxic T cell(CTL)activity and the inability to induce apoptosis of macrophages(Mac).Methods The Peripheral blood mononuclear cells(PBMC)of patient with drug-resistant tuberculosis were isolated by density gradient centrifugation. The specific killing CTL against autologous MTB-Ag were induced by culturing with Mac. The CTL against MTB-Ag response was measured by evaluated the expressions of the lytic molecules perfoin,granzyme B,and granulysin in CTLs as well as apoptosis markers TLR3 and Caspase-3 on macrophages,compared with patients bearing non-drug-resistant tuberculosis and healthy individuals. Results Our results demonstrate that compared with non-drug-resistant tuberculosis patients,MDR-MTB-Ag-stimulated autologous CTL show lower expression of perfoin,granzymeB andgranulysin together with lower expression of TLR2,Caspase-3 on autologous macrophages. Conclusion Impairing cellular immunity of CTL may be an immune escape mechanism of drug-resistant MTB-Ag against the host body,so as to maintain its continuous infection in the host.更多还原