Zhang Ka, Liu Yanqiong, Yang Xiaoan, Sun Haixia, Shu Xin, Zhang Yeqiong, Cao Hong, Wu Mengdi, Liu Nan, Zou Yong, Xu Qihuan, Li Gang
Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, P. R. China.
Department of Infectious Diseases, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, P. R. China.
Liver Int. 2020 Jun;40(6):1327-1338. doi: 10.1111/liv.14438. Epub 2020 Apr 15.
Little is known about the mechanisms of IL-17 secreting T cells accumulation in HBV-transfected livers. Here, we investigated the role of the chemokines CCL17, CCL20 and CCL22 in this process.
Peripheral blood and liver tissues were obtained from 30 chronic hepatitis B (CHB) patients and 15 healthy volunteers and were evaluated by flow cytometric analysis and immunohistochemistry. Chemokine production by monocyte-derived dendritic cells (MoDCs) cocultured with HBV-transfected or untransfected Huh7 cells was measured by quantitative real-time PCR and enzyme-linked immunosorbent assay. The chemotactic activity of the culture supernatants was also tested.
The proportions of IL-17 secreting CD4 (Th17) and CD8 (Tc17) T cells were both increased in liver and peripheral blood mononuclear cells of CHB patients compared to those in HVs. CHB patients showed higher intrahepatic levels of CCL17 mRNA, CCL22 mRNA, CCR6 mRNA and CCR4 mRNA than HVs. The expression of CCR6 and CCR4 on the surface of Th17 and Tc17 cells in CHB patients was also significantly higher than that in HVs. Significant correlations existed between the CCR4/CCR6 levels and both the alanine transaminase levels and HBV DNA loads. Contact between MoDCs and pBlue-HBV-transfected Huh7 cells induced the expression of CCL17 and CCL22 dependent on the dose of HBV DNA. However, CCL20 expression was lower in CHB patients than in HVs. Transwell experiments showed that upregulation of CCL17 and CCL22 enhanced the migration of IL-17 secreting T cells.
Contact of HBV-transfected cells with MoDCs induces CCL17 and CCL22 chemokine production, which may favour the recruitment of Th17 and Tc17 cells to liver tissue in CHB. Our results reveal the mechanism of IL-17 secreting T cells recruitment to liver tissue and thus provide new immunotherapy targets for CHB patients.
关于白细胞介素-17分泌性T细胞在乙肝病毒转染肝脏中积聚的机制，目前所知甚少。在此，我们研究了趋化因子CCL17、CCL20和CCL22在此过程中的作用。
从30例慢性乙型肝炎（CHB）患者和15名健康志愿者获取外周血和肝组织，通过流式细胞术分析和免疫组织化学进行评估。通过定量实时聚合酶链反应和酶联免疫吸附测定法，检测与乙肝病毒转染或未转染的Huh7细胞共培养的单核细胞衍生树突状细胞（MoDCs）产生趋化因子的情况。还测试了培养上清液的趋化活性。
与健康志愿者相比，CHB患者肝脏和外周血单个核细胞中分泌白细胞介素-17的CD4（Th17）和CD8（Tc17）T细胞比例均增加。CHB患者肝内CCL17信使核糖核酸、CCL22信使核糖核酸、CCR6信使核糖核酸和CCR4信使核糖核酸水平高于健康志愿者。CHB患者Th17和Tc17细胞表面CCR6和CCR4的表达也显著高于健康志愿者。CCR4/CCR6水平与丙氨酸转氨酶水平和乙肝病毒脱氧核糖核酸载量之间存在显著相关性。MoDCs与pBlue-乙肝病毒转染的Huh7细胞之间的接触，诱导了依赖乙肝病毒脱氧核糖核酸剂量的CCL17和CCL22表达。然而，CHB患者中CCL20表达低于健康志愿者。Transwell实验表明，CCL17和CCL22的上调增强了分泌白细胞介素-17的T细胞的迁移。
乙肝病毒转染细胞与MoDCs的接触诱导CCL17和CCL22趋化因子产生，这可能有利于Th17和Tc17细胞向CHB患者肝组织募集。我们的结果揭示了分泌白细胞介素-17的T细胞募集到肝组织的机制，从而为CHB患者提供了新的免疫治疗靶点。
