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。
Objective: To investigate the effect of proinflammation cytokine TNF-α on the antibacterial activity of urinary epithelial cells against intracellular Klebsiella pneurnoniae. 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 cell) 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 dilutions 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 pneurrumiae. 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.
出处
《四川生理科学杂志》
2013年第1期1-4,共4页
Sichuan Journal of Physiological Sciences
基金
国家自然科学基金(编号:30270688
30570790)