【摘要】 目的:研究TNF-α对膀胱上皮细胞内肺炎克雷伯杆菌生存的影响。方法:以肺炎克雷伯杆菌侵入体外培养的人膀胱上皮细胞(T24细胞)为模型,观察在TNF-α等细胞因子处理条件下,不同时间点细胞内细菌数量变化。结果:单独使用TNF-α使T24细胞内的肺炎克雷伯杆菌K5株细菌数量明显减少,联合使用TNF-α与IFN-γ使胞内活菌数量更显著的减少。而IL-1β对细胞内活菌数量无明显影响。过氧化氢酶可以有效抑制TNF-α与IFN-γ刺激的T24细胞抗菌作用,而一氧化氮合酶抑制剂L-NAME无抑制作用。结论:TNF-α能够增强膀胱上皮细胞对抗细胞内肺炎克雷伯杆菌,抗菌机制与细胞产生活性氧(ROS)有关。更多还原

【Abstract】 Objective: To investigate the effect of proinflammation cytokine TNF-α on the antibacterial activity of urinary epithelial cells against intracellular Klebsiella pneumoniae.Methods: Monolayers of T24 cells were grown to confluence in 24-well plate.Cells were infected with Klebsiella pneumoniae strain K5,a clinical isolate(approximately 100 bacteria per epithelial cel1) for 2 hours.Extracellular bacteria were killed by gentamicin and the cells were incubated with proinflammation cytokines(TNF-α,IFN-γ,IL-1β).After 24 and 48 hours from the initial infection,the cells were lysed with Triton X-100 and viable intracellular bacteria were quantified by plating appropriate di1utions on LB agar plates.Results: In comparison with control,the number of viable intracellular Klebsiella pneumoniae decreased significantly in the cells treated with TNF-α.Combination of TNF-α and IFN-γ further decreased the number of viable intracellular bacteria.On the other hand,IL-1β had no significant effect on the number of viable intracellular Klebsiella pneumoniae.Antibacterial activity induced by TNF-α and IFN-γ was significantly inhibited by catalase.Conclusion: The clearance of intracellular Klebsiella pneumoniae by human urinary epithelial cells could be enhanced by TNF-α and reactive oxygen species(ROS) were involved in the antibacterial activity.更多还原