铜绿假单胞菌生物被膜诱导肺泡上皮细胞分泌炎性细胞因子的研究

目的：通过研究经铜绿假单胞菌生物被膜作用后,肺泡上皮细胞分泌炎性细胞因子水平的变化,探讨铜绿假单胞菌生物被膜在感染性肺纤维化中的作用。方法：采用体外诱导铜绿假单胞菌形成生物被膜,应用乙醇沉淀法提取细菌被膜并纯化;选用人肺泡Ⅱ型上皮细胞株A549,采用ELISA法定量检测在铜绿假单胞生物被膜藻酸盐作用后上皮细胞上清液中炎症因子IL-1β、IL-6、IL-8和TNF-α的水平。结果：铜绿假单胞菌生物被膜藻酸盐作用后,A549细胞分泌IL-1β和TNF-α能力在48 h内持续升高,但IL-6和IL-8则在24 h达到高峰,此后下降。结论：铜绿假单胞菌生物被膜能诱导A549细胞分泌IL-1β、IL-6、IL-8和TNF-α能力增强或一过性增强,可能与其诱导肺泡炎症,进而促进成纤维细胞活化、增殖及转化有关。

Bacterial Biofilm Grown with Pseudomonas aeruginosa Stimulating Secretion of Inflammatory Cytokines from Alveolar Epithelial Cells

Objective： To observe the changes of secretion of inflammatory cytokines from alveolar epithelial cells after infected by Pseudomonas aeruginosa,and to explore the effect of bacterial biofilm on infectious pulmonary fibrosis.Methods： Pseudomonas aeruginosa biofilm was formed in vitro and then was purified with alcohol precipitation method.Human cell line A549 was used to be infected by the biofilm.The levels of IL-1β,IL-6,IL-8,and TNF-α in the supernatant was detected by ELISA.Results： After infection,the levels of IL-1β and TNF-α consistently increased in 48 h,while those of IL-6 and IL-8 was elevated in 24 h and then started to decrease afterwards.Conclusion： Pseudomonas aeruginosa biofilm can enhance the capacity of A549 cells to secrete IL-1β,TNF-α,IL-6,and IL-8 consistently or temporarily.It may induce the inflammatory response in pulmonary fibrosis.