Yoon Miri, Spear Patricia G
Department of Microbiology-Immunology, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
J Virol. 2002 Jul;76(14):7203-8. doi: 10.1128/jvi.76.14.7203-7208.2002.
Nectin-1, a cell adhesion molecule belonging to the immunoglobulin superfamily, can bind to virion glycoprotein D (gD) to mediate entry of herpes simplex viruses (HSV) and pseudorabies virus (PRV). Nectin-1 colocalizes with E-cadherin at adherens junctions in epithelial cells. The disruption of cell junctions can result in the redistribution of nectin-1. To determine whether disruption of junctions by calcium depletion influenced the susceptibility of epithelial cells to viral entry, Madin-Darby canine kidney cells expressing endogenous nectin-1 or transfected human nectin-1 were tested for the ability to bind soluble forms of viral gD and to be infected by HSV and PRV, before and after calcium depletion. Confocal microscopy revealed that binding of HSV and PRV gD was localized to adherens junctions in cells maintained in normal medium but was distributed, along with nectin-1, over the entire cell surface after calcium depletion. Both the binding of gD and the fraction of cells that could be infected by HSV-1 and PRV were enhanced by calcium depletion. Taken together, these results provide evidence that nectin-1 confined to adherens junctions in epithelial cells is not very accessible to virus, whereas dissociation of cell junctions releases nectin-1 to serve more efficiently as an entry receptor.
Nectin-1是一种属于免疫球蛋白超家族的细胞粘附分子,它能与病毒粒子糖蛋白D(gD)结合,介导单纯疱疹病毒(HSV)和伪狂犬病病毒(PRV)的进入。Nectin-1与E-钙粘蛋白在上皮细胞的黏着连接处共定位。细胞连接的破坏会导致Nectin-1的重新分布。为了确定钙缺失引起的连接破坏是否影响上皮细胞对病毒进入的敏感性,在钙缺失前后,对表达内源性Nectin-1的Madin-Darby犬肾细胞或转染人Nectin-1的细胞进行了检测,以评估它们结合可溶性病毒gD的能力以及被HSV和PRV感染的能力。共聚焦显微镜显示,HSV和PRV gD的结合在正常培养基中培养的细胞的黏着连接处定位,但在钙缺失后,与Nectin-1一起分布在整个细胞表面。钙缺失增强了gD的结合以及可被HSV-1和PRV感染的细胞比例。综上所述,这些结果表明,局限于上皮细胞黏着连接处的Nectin-1不易被病毒接触到,而细胞连接的解离会释放Nectin-1,使其更有效地作为进入受体发挥作用。