Martínez-Martín Nadia, Viejo-Borbolla Abel, Alcami Antonio
Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, Madrid, Spain.
J Gen Virol. 2016 Nov;97(11):3007-3016. doi: 10.1099/jgv.0.000616. Epub 2016 Sep 27.
Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2, respectively) are among the most prevalent human pathogens, causing a variety of diseases. HSV modulation of the chemokine network remains poorly understood. We have previously identified secreted glycoprotein G (SgG) as the first viral chemokine-binding protein that enhances chemokine function as a novel viral immunomodulatory mechanism. However, gG is also present at the viral envelope and its role in the virus particle remains unknown. Here we have addressed the chemokine-binding capacity of HSV particles and the functionality of such interaction in vitro. We adapted surface plasmon resonance assays and demonstrated the ability of HSV particles to bind a specific set of human chemokines with high affinity. Moreover, we identified gG as the envelope glycoprotein mediating such interaction, as shown by the lack of binding to a HSV-1 gG mutant. In contrast to HSV-1, HSV-2 gG is cleaved and the chemokine-binding domain is secreted (SgG2). However, we found that HSV-2 particles retain the ability to bind chemokines, potentially through SgG2 associated to the viral envelope or non-processed precursor protein. Moreover, we found that HSV particles increase cell migration independently of chemokine binding to envelope gG. This work provides insights into HSV manipulation of the host immune system.
1型和2型单纯疱疹病毒(分别为HSV-1和HSV-2)是最常见的人类病原体之一,可引发多种疾病。人们对HSV对趋化因子网络的调节作用仍知之甚少。我们之前已鉴定出分泌型糖蛋白G(SgG)是首个病毒趋化因子结合蛋白,它可增强趋化因子功能,这是一种新的病毒免疫调节机制。然而,gG也存在于病毒包膜上,其在病毒颗粒中的作用尚不清楚。在此,我们研究了HSV颗粒的趋化因子结合能力及其在体外这种相互作用的功能。我们采用表面等离子体共振测定法,证明了HSV颗粒能够以高亲和力结合一组特定的人类趋化因子。此外,我们鉴定出gG是介导这种相互作用的包膜糖蛋白,这一点可通过与HSV-1 gG突变体缺乏结合得到证明。与HSV-1不同,HSV-2 gG会被切割,趋化因子结合结构域会被分泌(SgG2)。然而,我们发现HSV-2颗粒保留了结合趋化因子的能力,可能是通过与病毒包膜相关的SgG2或未加工的前体蛋白。此外,我们发现HSV颗粒可独立于趋化因子与包膜gG的结合而增加细胞迁移。这项工作为HSV对宿主免疫系统的操控提供了见解。