中文摘要：

目的 研究CD4＋ CD25＋ Foxp3＋调节性T细胞（Treg）、效应性Th17细胞（Th17）和树突状细胞（DC）在胆道闭锁（BA）息儿免疫炎症发展中的作用.方法 收集32例BA和15例对照组患儿（非胆道疾病）肝脏和外周血标本.应用免疫组化、流式细胞术、QRT-PCR、免疫荧光染色检测两组患儿肝组织和外周血中Treg和Th17细胞亚群的数量、相关细胞因子和转录因子Foxp3、孤儿核受体（ROR-γt）表达水平,以及DC细胞Toll样受体3、7、8（TLR3、7、8）的表达.体外细胞共培养实验研究细胞功能及分化.结果 免疫组化显示队组肝组织汇管区Treg和Th17细胞明显比对照组增多,肝脏Foxp3、ROR-γ和IL-17的mRNA表达量也显著高于对照组患儿（P＜0.05）.BA组中血清TGF-β、IL-10（Treg相关因子）、IL-17（Th17相关因子）、IL-12、IFN-γ（Th1相关因子）和IL-6均显著高于对照组（P＜0.05）.其中IL-6升高24倍,最为明显.流式细胞学检查显示外周血Th17/CD4＋T比例显著高于对照组,而Treg/CD4＋T细胞比例无差异.体外细胞培养发现升高的IL-6与免疫细胞特别是DC细胞高表达TLR3、7、8有关,并且促进Th17细胞偏移.结论 BA患儿中Th17/CD4＋T细胞比例增多和IL-17水平增高可能在BA胆管的进行性炎症中发挥重要作用,DC细胞的活化促进了Th17分化.

英文摘要：

Objective To explore the contribution of regulation T cells （Treg）,Th17 and dendritic cells （DC） in progressive inflammation of biliary atresia.Methods Liver and blood samples were taken from 32 patients of biliary atresia （BA group） and 15 patients without liver diseases （control group）.Immunohistochemistry,QRT-PCR,flow cytometry,ELLISA and immunofluorescence were performed to detect the quantity of Treg and Th17 cells,the relative expression of cytokine,transcription factor Foxp3 and ROR-γt in liver and blood,and the expression of TLR3,TLR7,and TLR8 protein in DCs.Results Immunohistochemistry showed there were more Treg and Th17 cells in liver portal area of BA group than those in control group.The expressions of Foxp3,IL-17,ROR-γt in liver in BA group were significantly higher than those in control group in both protein and mRNA level （P〈0.05）.The expressions of IL-10,TGF-β （Treg）,IL-17 （Th17）,IFN-γ,IL-12 （Th1）,IL-6 in blood serum in BA group were significantly higher than those in control group （P〈0.05）,particularly IL-6 in BA group was 24 times than that in control group.Flow cytometry showed significant higher ratio of Th17/CD4＋ T cells in BA group than that in control group （P〈0.05）,while the ratio ofTreg/CD4＋ T cells had no significant difference （P〉0.05）.Cell co-culture showed IL-6 expression was related to the high expression of TLR3,TLR7,and TLR8 in DCs,and enabled the Th17 differentiation.Conclusions The increased level of Th17/CD4＋ T cells ratio and IL-17 expression in BA children may play an important role in progressive inflammation of BA.Activation of DCs promotes the Th17 differentiation.