Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, University of Leuven (KU Leuven), Belgium.
Translational Cell & Tissue Research, Department of Imaging & Pathology, University of Leuven (KU Leuven), Belgium.
Exp Cell Res. 2018 Nov 15;372(2):168-177. doi: 10.1016/j.yexcr.2018.09.023. Epub 2018 Oct 2.
The CCL20/CCR6 chemokine/receptor axis has previously been shown to contribute to the initiation and progression of hepatocellular carcinoma (HCC) through the recruitment of CCR6-positive leukocytes to the tumor microenvironment. In particular, high serum levels of CCL20 are reported in patients with HCC induced by the hepatitis C virus (HCV). A potential non-immune role for the CCL20/CCR6 axis in HCC development has not yet been investigated. Microarray analysis (Benkheil et al., paper submitted for publication), revealed that CCL20 is highly upregulated in hepatoma cells infected with HCV compared with non-infected hepatoma cells. To determine the role of the CCL20/CCR6 axis in HCV-related HCC, we first explored which cell populations express CCR6 in human liver tissue with chronic disease or HCC. Immunohistochemical (IHC) analysis revealed that CCR6 is present on endothelial cells (ECs) of portal blood vessels in livers with chronic HCV infection and in HCV- and alcoholic-HCC tissue. In addition, we found CCR6 to be expressed on primary macrovascular (HUVECs) and microvascular ECs (HMVEC-ds) where it co-expressed with the endothelial marker CD31. In vitro angiogenesis experiments revealed that CCL20 is a direct pro-angiogenic molecule that induces EC invasion, sprouting and migration through CCR6. Moreover, using the angiogenesis matrigel plug assay in immunodeficient NMRI-nu mice, we clearly showed that CCL20 induces blood vessel formation, by attracting CCR6-positive ECs. Finally, we demonstrated that HCV-induced CCL20 protein expression and secretion in hepatoma cells could be abolished by antiviral treatment, indicating that CCL20 expression is dependent on HCV replication. In contrast to HCV, HBV-infection resulted in a decreased expression of CCL20, implying a virus-specific effect. Taken together, we identified HCV-induced CCL20 as a direct pro-angiogenic factor that acts on endothelial CCR6. These results suggest that the CCL20/CCR6 axis contributes to hepatic angiogenesis, promoting the hypervascular state of HCV-HCC.
CCL20/CCR6 趋化因子/受体轴先前已被证明通过募集 CCR6 阳性白细胞到肿瘤微环境，有助于肝细胞癌（HCC）的起始和进展。特别是，丙型肝炎病毒（HCV）诱导的 HCC 患者的血清 CCL20 水平升高。CCL20/CCR6 轴在 HCC 发展中的非免疫作用尚未得到研究。微阵列分析（Benkheil 等人，已提交发表的论文）表明，与未感染的肝癌细胞相比，HCV 感染的肝癌细胞中 CCL20 高度上调。为了确定 CCL20/CCR6 轴在 HCV 相关 HCC 中的作用，我们首先探索了哪些细胞群在慢性疾病或 HCC 的人类肝组织中表达 CCR6。免疫组织化学（IHC）分析显示，慢性 HCV 感染和 HCV 和酒精性 HCC 组织中的门静脉血管内皮细胞（ECs）存在 CCR6。此外，我们发现 CCR6 在原发性大血管（HUVECs）和微血管 EC（HMVEC-ds）上表达，与内皮标记物 CD31 共表达。体外血管生成实验表明，CCL20 是一种直接的促血管生成分子，通过 CCR6 诱导 EC 侵袭、发芽和迁移。此外，我们在免疫缺陷型 NMRI-nu 小鼠的血管生成 Matrigel plugs 测定中清楚地表明，CCL20 通过吸引 CCR6 阳性 EC 诱导血管形成。最后，我们证明 HCV 诱导的肝癌细胞中 CCL20 蛋白表达和分泌可以通过抗病毒治疗消除，表明 CCL20 表达依赖于 HCV 复制。与 HCV 相反，HBV 感染导致 CCL20 表达减少，暗示存在病毒特异性效应。总之，我们确定 HCV 诱导的 CCL20 是一种直接的促血管生成因子，作用于内皮细胞 CCR6。这些结果表明，CCL20/CCR6 轴有助于肝血管生成，促进 HCV-HCC 的高血管状态。
