Liu Yalan, Li Mei, Zhang Di, Zhang Mudan, Hu Qinxue
State Key Laboratory of Virology, Chinese Academy of Sciences, Wuhan Institute of Virology, Wuhan, 430071, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Virol J. 2016 Sep 15;13(1):154. doi: 10.1186/s12985-016-0610-7.
HSV-2 is the major cause of genital herpes. We previously demonstrated that the host viral restriction factor tetherin restricts HSV-2 release and is antagonized by several HSV-2 glycoproteins. However, the mechanisms underlying HSV-2 glycoproteins mediated counteraction of tetherin remain unclear. In this study, we investigated whether tetherin restricts the cell-to-cell spread of HSV-2 and the mechanisms underlying HSV-2 gD mediated antagonism of tetherin.
Infectious center assays were used to test whether tetherin could affect cell-to-cell spread of HSV-2. Coimmunoprecipitation assays were performed to map the tetherin domains required for HSV-2 gD-mediated downregulation. Immunoflurence assays were performed to detect the accumulation of tetherin in lysosomes or proteasomes. All experiments were repeated for at least three times and the data were performed statistical analysis.
Tetherin not only restricts HSV-2 release but also its cell-to-cell spread. In turn, HSV-2 gD targets the CC domain of tetherin and promotes its degradation in the lysosome. Findings in this study have increased our understanding of tetherin restriction and viral countermeasures.
单纯疱疹病毒2型（HSV-2）是生殖器疱疹的主要病因。我们之前证明宿主病毒限制因子束缚素可限制HSV-2的释放，并且几种HSV-2糖蛋白可拮抗束缚素。然而，HSV-2糖蛋白介导的对束缚素的拮抗作用的潜在机制仍不清楚。在本研究中，我们调查了束缚素是否限制HSV-2的细胞间传播以及HSV-2糖蛋白D（gD）介导的对束缚素的拮抗作用的潜在机制。
采用感染中心试验来检测束缚素是否会影响HSV-2的细胞间传播。进行免疫共沉淀试验以确定HSV-2 gD介导的下调所需的束缚素结构域。进行免疫荧光试验以检测束缚素在溶酶体或蛋白酶体中的积累。所有实验至少重复三次，并对数据进行统计分析。
1）束缚素限制HSV-2的细胞间传播；2）HSV-2 gD与束缚素的CC结构域特异性相互作用；3）HSV-2 gD促进束缚素进入溶酶体降解途径。
束缚素不仅限制HSV-2的释放，还限制其细胞间传播。反过来，HSV-2 gD靶向束缚素的CC结构域并促进其在溶酶体中的降解。本研究结果增进了我们对束缚素限制作用和病毒应对措施的理解。
