Department of Marine Biology, College of Oceanography, Hohai University, Nanjing 210098, PR China.
Department of Marine Biology, College of Oceanography, Hohai University, Nanjing 210098, PR China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China.
Virus Res. 2022 Jul 2;315:198794. doi: 10.1016/j.virusres.2022.198794. Epub 2022 Apr 30.
Channel catfish virus (CCV), an important member of the family Alloherpesviridae, causes a lethal infection in channel catfish. As with most animal viruses, the initial step of infection by CCV is entry into host cells, which is also a promising antiviral target for CCV disease. This study investigated the mechanism of host cell invasion by CCV using a series of biochemical inhibitor assays in channel catfish cells. CCV infection in host cells was does-dependently inhibited when cells were treated with endosomal acidification inhibitors (5 μM chloroquine, 50 nM bafilomycin A1, and 1 mM ammonium chloride) and hypertonic medium (50 mM sucrose) , which suggests that CCV invades host cells in a manner dependent on low-pH and the endocytic pathway. Moreover, when the cells were pretreated with inhibitors of clathrin-mediated endocytosis, including chlorpromazine (2 μM) and dynasore (50 μM), the CCV infection in the host cells was strongly inhibited. In contrast, the destruction of cellular cholesterol by methyl-β-cyclodextrin and nystatin and inhibition of macropinocytosis had no effect on viral entry. Altogether, these findings indicate that CCV infects host cells via clathrin-mediated endocytosis in a low-pH-dependent manner, suggesting that this CCV entry pathway offers an antiviral target against CCV disease.
斑点叉尾鮰病毒（CCV）是疱疹病毒科的一个重要成员，可引起斑点叉尾鮰的致命感染。与大多数动物病毒一样，CCV 感染宿主细胞的初始步骤是进入宿主细胞，这也是 CCV 疾病的一个有前途的抗病毒靶点。本研究通过一系列生化抑制剂试验在斑点叉尾鮰细胞中研究了 CCV 对宿主细胞入侵的机制。当用内体酸化抑制剂（5 μM 氯喹、50 nM 巴弗洛霉素 A1 和 1 mM 氯化铵）和高渗培养基（50 mM 蔗糖）处理细胞时，CCV 感染宿主细胞呈剂量依赖性抑制，这表明 CCV 以依赖于低 pH 值和内吞作用的方式入侵宿主细胞。此外，当用网格蛋白介导的内吞作用抑制剂预处理细胞时，包括氯丙嗪（2 μM）和 dynasore（50 μM）时，宿主细胞中的 CCV 感染被强烈抑制。相比之下，细胞胆固醇的破坏由甲基-β-环糊精和制霉菌素以及巨胞饮作用的抑制对病毒进入没有影响。总之，这些发现表明 CCV 通过网格蛋白介导的内吞作用以依赖于低 pH 值的方式感染宿主细胞，表明该 CCV 进入途径为针对 CCV 疾病提供了抗病毒靶点。
