A Single-Amino-Acid Substitution in Herpes Simplex Virus 1 Envelope Glycoprotein B at a Site Required for Binding to the Paired Immunoglobulin-Like Type 2 Receptor α (PILRα) Abrogates PILRα-Dependent Viral Entry and Reduces Pathogenesis
A Single-Amino-Acid Substitution in Herpes Simplex Virus 1 Envelope Glycoprotein B at a Site Required for Binding to the Paired Immunoglobulin-Like Type 2 Receptor α (PILRα) Abrogates PILRα-Dependent Viral Entry and Reduces Pathogenesis
复制标题
DOI：
10.1128/jvi.01166-10
复制
发表时间：
2010-10-01
影响因子：
5.4
通讯作者：
Kawaguchi, Yasushi
中科院分区：
文献类型：
--
作者：
Arii, Jun;Wang, Jing;Kawaguchi, Yasushi
配对免疫球蛋白样2型受体α（PILR α）是一种单纯疱疹病毒1型（HSV-1）进入受体，与HSV-1包膜糖蛋白B（gB）上的O-聚糖相关。gB中的两个苏氨酸残基（Thr-53和Thr-480）是添加主要gB O-聚糖所需的，对于结合可溶性PILR α是必需的。然而，两种苏氨酸在PILR α依赖性病毒进入中的作用仍有待阐明。因此，我们构建了携带单独的gB Thr-53（gB-T53 A）或gB Thr-53和Thr-480两者（gB-T53/480 A）的丙氨酸置换的重组HSV-1，并证明这些突变消除了表达PILR α的CHO细胞中的病毒进入。相比之下，突变对病毒进入表达HSV-1 gD的已知宿主细胞受体的CHO细胞、病毒进入表达髓鞘相关糖蛋白（MAG）（另一种HSV-1 gB受体）的HL 60细胞、病毒附着于硫酸乙酰肝素以及病毒在PILR α阴性细胞中的复制没有影响。这些结果支持gB Thr-53和Thr-480以及gB O-糖基化（可能在这些位点）对于PILR α依赖性病毒进入至关重要的假设。有趣的是，在小鼠角膜接种后，gB-T53 A和gB-T53/480 A突变显著降低了角膜中的病毒复制、疱疹基质角膜炎的发展和神经侵袭性。因此，HSV-1以PILR α依赖性方式进入细胞和在gB上获得特异性碳水化合物的能力与实验鼠模型中病毒复制和毒力的增加有关。
Paired immunoglobulin-like type 2 receptor alpha (PILR alpha) is a herpes simplex virus 1 (HSV-1) entry receptor that associates with O-glycans on HSV-1 envelope glycoprotein B (gB). Two threonine residues (Thr-53 and Thr-480) in gB, which are required for the addition of the principal gB O-glycans, are essential for binding to soluble PILR alpha. However, the role of the two threonines in PILR alpha-dependent viral entry remains to be elucidated. Therefore, we constructed a recombinant HSV-1 carrying an alanine replacement of gB Thr-53 alone (gB-T53A) or of both gB Thr-53 and Thr-480 (gB-T53/480A) and demonstrated that these mutations abrogated viral entry in CHO cells expressing PILR alpha. In contrast, the mutations had no effect on viral entry in CHO cells expressing known host cell receptors for HSV-1 gD, viral entry in HL60 cells expressing myelin-associated glycoprotein (MAG) (another HSV-1 gB receptor), viral attachment to heparan sulfate, and viral replication in PILR alpha-negative cells. These results support the hypothesis that gB Thr-53 and Thr-480 as well as gB O-glycosylation, probably at these sites, are critical for PILR alpha-dependent viral entry. Interestingly, following corneal inoculation in mice, the gB-T53A and gB-T53/480A mutations significantly reduced viral replication in the cornea, the development of herpes stroma keratitis, and neuroinvasiveness. The abilities of HSV-1 to enter cells in a PILR alpha-dependent manner and to acquire specific carbohydrates on gB are therefore linked to an increase in viral replication and virulence in the experimental murine model.