呼吸道合胞病毒合并肺炎克雷伯菌感染所致肺炎与TLR4-NF-κB信号通路关系的初步研究  

A preliminary study on the relations between pneumonia induced by RSV combined with Klebsiella pneumonia infection and TLR4-NF-κB signal transduction pathway

作　　者：王云[1] 黄升海[1] 吴璇[1] 李振兴 于莉[1] 汪旻旻 

机构地区：[1]安徽医科大学基础医学院微生物学教研室,合肥230032 [2]安徽省第二人民医院输血科,合肥230061

出　　处：《安徽医科大学学报》2015年第9期1252-1258,共7页Acta Universitatis Medicinalis Anhui

基　　金：安徽省自然科学基金项目(编号:1308085MH129);安徽高校省级自然科学研究重点项目(编号:KJ2012A152)

摘　　要：目的探讨呼吸道合胞病毒(RSV)合并肺炎克雷伯菌(Kp)感染SD大鼠后,初步研究其所致肺炎与TLR4-NF-κB信号转导通路的关系。方法 60只雄性SD大鼠随机分为正常对照组、RSV组、Kp组及RSV+Kp组,以RSV、Kp滴鼻感染SD大鼠,分别于感染后第0、1、3、5、7天不同时间点,测量其体重、肺指数(LI)的变化;HE染色观察肺的病理学改变;RT-PCR法检测肺组织中TLR4、NF-κB的mRNA表达;Western blot检测NF-κB蛋白的表达;ELISA法检测肿瘤坏死因子-α(TNF-α)和白细胞介素-1β(IL-1β)含量的变化。结果与正常对照组相比,RSV组和Kp组均存在弥漫性肺泡间隔增厚和炎症细胞浸润,且随感染时间的延长,肺泡结构破坏逐渐加重,LI、TLR4 mRNA、NF-κB mRNA、NF-κB蛋白、TNF-α和IL-1β的表达均升高,并与RSV和Kp感染之间存在时间依赖性关系;RSV+Kp组LI、TLR4 mRNA、NF-κB mRNA、NF-κB蛋白、TNF-α和IL-1β的表达量进一步升高,肺组织炎症明显加剧。结论 RSV和Kp混合感染具有协同作用,加重肺部炎症;RSV合并Kp感染可能通过TLR4-NF-κB途径诱导肺部炎症反应,释放细胞因子TNF-α和IL-1β等。Objective This study investigates SD rats infected with pneumonia respiratory syncytial virus （RSV） combined with klebsiella pneumonia （Kp） to explore its relationship with TLR4-NF-κB signal transduction pathway. Methods A total of 60 SD rats were divided into four groups randomly：control group, RSV group, Kp group and Kp ＋ RSV group. All animals were infected with RSV or Kp using intranasal method. We observed the weights, lung index, histopathological changes in the lung tissues by HE staining, the expression of TLR4, NF-κB mRNA with RT-PCR, NF-κB protein by Western blot analysis in the lung tissues and the concentrations of TNF-α, IL-1β with ELISA at 0,1,3,5,7 days after RSV or Kp post-infections. Results Compared with control group, dif- fuse thickening of alveolar interval and inflammatory cells infiltration were observed in RSV and Kp group, and with the extension of infection time, the infection alveolar structure increased gradually. The expression of LI, TLR4 mR- NA, NF-kB mRNA, NF-kB protien,TNF-α and IL-1β increased and the relationship between RSV and Kp showed time dependence; in RSV ＋ Kp group , the expression of LI, TLR4 mRNA, NF-kB mRNA, NF-kB protein, TNF-αand IL-1β increased gradully and lung tissue inflammation increased significantly. Conclusion RSV combined with Kp infection has synergistic effects and aggravates pulmonary inflammation. RSV combined with Kp infection can induce pulmonary defence cells release cytokines TNF-α and IL-1β by TLR4-NF-κB signal transduction pathway.

关 键 词：呼吸道合胞病毒 肺炎克雷伯菌 肺炎 TLR4 NF-ΚB 炎性因子 

分 类 号：R373.14[医药卫生—病原生物学]