Krummenacher C, Nicola A V, Whitbeck J C, Lou H, Hou W, Lambris J D, Geraghty R J, Spear P G, Cohen G H, Eisenberg R J
Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
J Virol. 1998 Sep;72(9):7064-74. doi: 10.1128/JVI.72.9.7064-7074.1998.
Several cell membrane proteins have been identified as herpes simplex virus (HSV) entry mediators (Hve). HveA (formerly HVEM) is a member of the tumor necrosis factor receptor family, whereas the poliovirus receptor-related proteins 1 and 2 (PRR1 and PRR2, renamed HveC and HveB) belong to the immunoglobulin superfamily. Here we show that a truncated form of HveC directly binds to HSV glycoprotein D (gD) in solution and at the surface of virions. This interaction is dependent on the native conformation of gD but independent of its N-linked glycosylation. Complex formation between soluble gD and HveC appears to involve one or two gD molecules for one HveC protein. Since HveA also mediates HSV entry by interacting with gD, we compared both structurally unrelated receptors for their binding to gD. Analyses of several gD variants indicated that structure and accessibility of the N-terminal domain of gD, essential for HveA binding, was not necessary for HveC interaction. Mutations in functional regions II, III, and IV of gD had similar effects on binding to either HveC or HveA. Competition assays with neutralizing anti-gD monoclonal antibodies (MAbs) showed that MAbs from group Ib prevented HveC and HveA binding to virions. However, group Ia MAbs blocked HveC but not HveA binding, and conversely, group VII MAbs blocked HveA but not HveC binding. Thus, we propose that HSV entry can be mediated by two structurally unrelated gD receptors through related but not identical binding with gD.
几种细胞膜蛋白已被鉴定为单纯疱疹病毒（HSV）的进入介质（Hve）。HveA（以前称为HVEM）是肿瘤坏死因子受体家族的成员，而脊髓灰质炎病毒受体相关蛋白1和2（PRR1和PRR2，重新命名为HveC和HveB）属于免疫球蛋白超家族。在此我们表明，截短形式的HveC在溶液中以及病毒粒子表面直接与HSV糖蛋白D（gD）结合。这种相互作用依赖于gD的天然构象，但与其N-连接糖基化无关。可溶性gD和HveC之间的复合物形成似乎涉及一个HveC蛋白结合一个或两个gD分子。由于HveA也通过与gD相互作用介导HSV进入，我们比较了这两种结构不相关的受体与gD的结合情况。对几种gD变体的分析表明，gD N端结构域的结构和可及性对于HveA结合至关重要，但对于HveC相互作用并非必需。gD功能区II、III和IV中的突变对与HveC或HveA的结合具有相似的影响。用中和抗gD单克隆抗体（MAb）进行的竞争试验表明，Ib组的MAb可阻止HveC和HveA与病毒粒子结合。然而，Ia组MAb可阻断HveC但不能阻断HveA的结合，相反，VII组MAb可阻断HveA但不能阻断HveC的结合。因此，我们提出HSV进入可由两种结构不相关的gD受体通过与gD相关但不完全相同的结合来介导。
