Toll样受体7,9与人细小病毒B19在桥本甲状腺炎发病机理中的作用

摘要

Objective:To explore the relationship between B19 antigen and TLR7,9 expression in Hashimoto's thyroiditis(HT).Methods:Total of 41 formalin-fixed and paraffin-embedded HT specimens and 20 control specimens were collected.B19,TLR7 and TLR9 were detected by EnVision immunohistochemistry (IHC) staining and co -expression between them was analyzed on serial sections of the thyroid specimens.The immunoflurenscence (IF)double-staining assay and confocal laser scanning microscopy were conducted to detect the co-localization of B19 and TLR7,B19 and TLR9 in cold ethanol-fixed,paraffin-embedded HT sections.The relationship between B19 and TLR9 was detected by co-immunoprecipitation (co-IP).Results:The positive rates of B19 and TLR9 in HT group were 80.49％ (33/41) and 82.93％ (34/41)respectively,while the control group was negative (P ＜ 0.01).B19 antigen expression was closely related to TLR9 expression (r =0.594,P =0.001).IF double-staining assay showed that B19 and TLR9 co-existed in the cytoplasm of injured epithelial cells in HT.Co-IP assay showed that B19 and TLR9 worked together in the pathogenesis of HT.However,TLR7 in HT group and the control group was negative.Conclusion:TLR9 may be a receptor for recognizing B19 antigen in the pathogenesis of HT.%目的:探讨桥本甲状腺炎(Hashimoto's thyroiditis,HT)中人细小病毒B19(parvovirus B19,B19)抗原与TLR7,9(Toll-like receptor7,9)表达的相关性.方法:采用连续切片免疫组织化学方法,检测41例单纯桥本甲状腺炎及20例甲状腺腺瘤旁正常甲状腺组织中B19抗原及TLR7和TLR9的表达,并对其进行相关性分析.收集3例新鲜HT组织做免疫荧光双标记染色,用激光共聚焦显微镜分别检测B19抗原和TLR7,B19抗原和TLR9的共定位关系.另外,用免疫共沉淀检测3例新鲜标本中B19抗原和TLR9的相互作用.结果:B19抗原在桥本甲状腺炎组的阳性表达率为80.49％(33/41)；TLR9在桥本甲状腺炎组的阳性表达率为82.93％ (34/41)；正常甲状腺组两者均阴性,两者差异非常显著(P＜0.01).B19抗原的阳性表达与TLR9的阳性表达存在非常显著的正相关关系(r =0.594,P=0.001).免疫荧光双标记激光共聚焦显微镜观察发现,B19抗原和TLR9蛋白明确共定位于桥本甲状腺炎嗜酸性变的滤泡上皮细胞的胞质中.免疫共沉淀结果进一步显示B19抗原与TLR9存在相互作用.TLR7在桥本甲状腺炎组的嗜酸性变的甲状腺滤泡上皮细胞和正常甲状腺组织表达均阴性.结论:TLR9通过识别B19抗原在HT的发病中起作用,TLR9很可能是B19病毒感染的识别受体.