Suppression of hepatitis C virus replication by cyclosporine A

环孢菌素 A 抑制丙型肝炎病毒复制

基本信息

批准号：
16590580
负责人：
OOOKA Shinya
金额：
$ 2.3万
依托单位：
Tokyo Medical and Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

Cyclosporin A specifically suppresses hepatitis C virus replication in vitro at clinically achievable concentrations. In this study, we investigated the mechanisms of action of cyclosporin A against HCV replication. The in-vitro effects of cyclosporin A on HCV replication were analyzed using HCV replicon system that expresses chimeric luciferase reporter protein. The significant effects of cyclosporin A on expression of an HCV replicon, and the absence of such effects of FK506 which shares mechanisms of action with cyclosporin A, suggested the involvement of intracellular ligands of cyclosporin A, the cyclophilins. Transient and stable knock-down of the expression of cytoplasmic cyclophilins A, B and C by shRNA-expressing vectors suppressed HCV replication significantly. A cyclosporin analogue, cyclosporin D, which lacks immunosuppressive activity but exhibits cyclophilin binding, induced a similar suppression of HCV replication. Furthermore, cyclosporin A treatment of Huh7 cells induced an unfolded protein response exemplified by expression of cellular BiP/GRP78. Treatment of cells with thapsigargin and mercaptoethanol, which induce the unfolded protein responses, suppressed HCV replication, suggesting that the cyclosporin-induced unfolded protein responses mignt contribute to the suppression of HCV protein processing and replication. The anti-HCV activity of cyclosporin A is mediated through a specific blockade of cyclophilins and these molecules may constitute novel targets for anti-HCV therapeutics.

环孢菌素 A 在临床可达到的浓度下特异性抑制体外丙型肝炎病毒复制。在这项研究中，我们研究了环孢菌素 A 对抗 HCV 复制的作用机制。使用表达嵌合荧光素酶报告蛋白的HCV复制子系统分析了环孢菌素A对HCV复制的体外影响。环孢菌素A对HCV复制子表达的显着影响，以及与环孢菌素A共享作用机制的FK506不存在这种影响，表明环孢菌素A的细胞内配体（亲环蛋白）的参与。 shRNA表达载体瞬时且稳定地敲低细胞质亲环蛋白A、B和C的表达，显着抑制HCV复制。环孢菌素类似物环孢菌素 D 缺乏免疫抑制活性，但具有亲环蛋白结合作用，可诱导类似的 HCV 复制抑制。此外，Huh7 细胞的环孢菌素 A 处理诱导未折叠蛋白反应，细胞 BiP/GRP78 的表达就是例证。用毒胡萝卜素和巯基乙醇处理细胞，诱导未折叠蛋白反应，抑制HCV复制，这表明环孢菌素诱导的未折叠蛋白反应可能有助于抑制HCV蛋白加工和复制。环孢菌素 A 的抗 HCV 活性是通过亲环蛋白的特异性阻断介导的，这些分子可能构成抗 HCV 治疗的新靶标。