华支睾吸虫感染小鼠肝脏中TLR2 mRNA动态表达的初步研究

An initial study of dynamic expression of TLR2 mRNA in the livers of mice infected with Clonorchis sinensis

目的观察华支睾吸虫感染小鼠肝脏中TLR2 mRNA的动态表达。方法建立华支睾吸虫感染小鼠模型,在感染不同时间点(1、2、4、7、14、28、568、4 d)取肝脏,采用逆转录聚合酶链反应检测肝脏TLR2 mRNA的表达,同时行HE染色观察感染小鼠各时间点肝脏病理学变化。结果与未感染对照组相比,感染组自感染后第7 d起TLR2 mRNA表达升高(P<0.05),至第28 d达到高峰,之后开始下降,至第56 d仍高于未感染对照组(P<0.05),第84 d下降至未感染对照组相近水平。病理学观察发现,感染小鼠肝脏于第4 d始,汇管区轻度炎症反应;第7 d,炎症反应加重,或见嗜酸性脓肿;第14 d,嗜酸性脓肿增多,纤维组织增生,周围小胆管增生;第28 d,胆管壁增厚,周围炎性渗出明显;第56 d,胆管上皮不同程度增生,增生的上皮呈腺样结构;第84 d,胆管周围炎性细胞减少,纤维增多,管壁增厚。结论 TLR2 mRNA在华支睾吸虫感染过程中表达升高,推测TLR2可能参与调控华支睾吸虫感染引发的Th1/Th2免疫应答和病理改变。

Objective The dynamic expression of TLR2 mRNA in liver of mice infected with Clonorchis sinensis was investigated to provide a basis for the role of TLR2 in the pathogenesis of clonorchiasis sinensis.Methods A well characterized mouse model of clonorchiasis sinensis was used in this study.Livers were removed from mice at various times post-infection（1 d,2 d,4 d,7 d,14 d,28 d,56 d,and 84 d）.The dynamic expression of TLR2 mRNA in livers was detected with RT-PCR.Pathological changes in the liver were observed with HE staining.The dynamic expression of TLR2 mRNA in livers was detected with RT-PCR.Results The TLR2 mRNA level in mice infected with C.sinensis increased on 7（P0.05） compared to the control group and peaked on day 28;it then subsequently decreased but was still higher than that in the control group on day 56（P0.05）.The TLR2 mRNA level decreased to a level like that in the control group on day 84.Four days post-infection（p.i.）,mild inflammation was observed in the portal region of the liver.Seven days p.i.,the inflammation worsened and eosinophilic abscesses were observed.At 14d p.i.,eosinophilic abscesses increased,fibrous tissue increased and small bile ducts proliferated.By 28d p.i.,walls of hepatic bile ducts had thickened and inflammatory exudate was evident around the ducts.At 56d p.i.,biliary epithelium had proliferated unevenly.There were adenoid structures in proliferating epithelium.At 84d p.i.,infiltration of inflammatory cells around bile ducts decreased whereas fibrous tissue had increased and bile duct walls were thicker.Conclusion TLR2 might play a role in the regulation Th1/Th2 immune response and pathogenesis of clonorchiasis sinensis.