TLR2及TLR4在侵袭性肺曲霉病小鼠中的表达

摘要

目的 研究Toll样受体(TLR)2和TLR4在侵袭性肺曲霉病小鼠中的表达,探讨TLR2和TLR4在侵袭性肺曲霉病中的作用. 方法 将小鼠分为3组:A组为正常对照组;B组为未免疫抑制但感染烟曲霉菌组;c组为侵袭性肺曲霉病(IPA)模型组,给予免疫抑制并感染烟曲霉菌.在感染后8、24、48和72 h时相点,处死小鼠,取肺组织,采用组织病理学方法观察肺组织的病理损伤,RT-PCR法检测肺组织各个时相点的TLR2、TLR4、TNF.ot和β-tublin的表达.TLR2、TLR4、TNF-α的PCR产物电泳条带的扫描密度值与同时扩增的β-tublin电泳条带的扫描密度值的比值用以表示TLR2、TLR4和TNF-α的相对表达水平. 结果 病理观察结果显示,对照组小鼠的肺组织结构正常;正常小鼠感染烟曲霉菌后,小鼠的肺组织有炎症细胞浸润、出血等炎症反应,但未见孢子萌芽生成菌丝;而IPA模型小鼠的肺组织病理损伤严重,可见炎症细胞浸润、肺泡塌陷伴随出血,孢子聚积并萌芽生成菌丝.8、24、48 h 3个时间点的TLR4和24、48 h两个时相点的TNF-α在IPA模型小鼠肺组织中的表达要低于烟曲霉菌感染的正常小鼠(P<0.05),而TLR2在烟曲霉菌感染的正常小鼠和IPA模型小鼠肺组织中呈现低表达,但24、72 h时相点的TLR2在IPA模型小鼠的表达要低于烟曲霉菌感染的正常小鼠(P<0.05). 结论 TLR4及其下游分子TNF-α在IPA模型小鼠肺组织中低表达,在组织病理镜检中可见肺曲霉病典型肺组织病理损伤和孢子生成菌丝.%Objective To study the roles of TLR2 and TLR4 in the progress of invasive pulmonary aspergillosis(IPA) in experimental mice.Methods The mice were divided into three groups including the group of normal mice,the group of normal mice infected with A.fumigatus and the group of IPA mice.The mice were sacrificed at four time points(8 h,24 h,48 h and 72 h) after infection.The lung tissues from each group were collected for pathological analysis and RT-PcR for detecting the expression level of,TLR2,TLR4 and β-tublin.The ratio of density value of band of each PCR product on electrophoresis to the density value of β-tublin was used to evaluate the expression level of each gene like TLR2.TLR4 and TNF-α.Re-suits The pathological analysis showed the normal structure and no inflananatory reaction in the lungs in the group of normal mice.The infiltration of inflammatory cells,weak injuries and no germination of spore into hypha in the lungs of normal mice infected with A.fumigatus,and serious injuries like destruction of alveolar structure,bleeding,infiltration of inflammatory cells and germination of spore into hypha in the lungs of IPA mice.The expression level of TLR4 at 8 h,24 h,48 h and TNF-α at 24 h and 48 h were lower in IPA mice than that in healthy mice with infection(P<0.05).Conclusion There was low expression of TLR4 and TNF-α in IPA mice lung tissues.Typical pathological injuries in the lungs and germination of spore into hy-pha in IPA mice were observed by the microscope.