Cellular Localization of Nectin-1 and Glycoprotein D during Herpes Simplex Virus Infection

Abstract

During viral entry, herpes simplex virus (HSV) glycoprotein D (gD) interacts with a specific cellular receptor such as nectin-1 (PRR1/HveC/CD111) or the herpesvirus entry mediator A (HVEM/HveA). Nectin-1 is involved in cell-to-cell adhesion. It is located at adherens junctions, where it bridges cells through homophilic or heterophilic interactions with other nectins. Binding of HSV gD prevents nectin-1-mediated cell aggregation. Since HSV gD affects the natural function of nectin-1, we further investigated the effects of gD expression on nectin-1 during HSV infection or in transfected cells. We also studied the importance of the interaction between nectin-1 and the cytoplasmic protein afadin for HSV entry and spread as well as the effects of infection on this interaction. In these investigations, we used a panel of cells expressing nectin-1 or nectin-1-green fluorescent protein fusions as the only mediators of HSV entry. During HSV infection, nectin-1 localization at adherens junction was dramatically altered in a manner dependent on gD expression. Nectin-1 and gD colocalized at cell contact areas between infected and noninfected cells and at the edges of plaques. This specific accumulation of gD at junctions was driven by expression of nectin-1 in trans on the surface of adjacent cells. Reciprocally, nectin-1 was maintained at junctions by the trans expression of gD in the absence of a cellular natural ligand. Our observations indicate that newly synthesized gD substitutes for nectin-1 of infected cells at junctions with noninfected cells. We propose that gD attracts and maintains the receptor at junctions where it can be used for virus spread.Binding of a specific cell surface receptor to herpes simplex virus (HSV) envelope glycoprotein D (gD) is an essential step in the process of viral entry into mammalian cells (5, 62). This interaction is required but not sufficient for membrane fusion, an event which also requires gB and the gH/gL complex (48, 70). Cellular receptors for HSV gD include herpesvirus entry mediator A (HVEM/HveA) (47), nectin-1 (PRR1/HveC/ CD111) (23), and nectin-2 (PRR2/HveB/CD112) (72), as well as a specific type of heparan sulfate modified by 3-OST-3 (D-glucosaminyl 3-O-sulfotransferase 3) (60). HVEM is a lymphotoxin receptor that belongs to the tumor necrosis factor receptor family (6,41,47), whereas nectins form a subgroup of immunoglobulin (Ig)-like molecules (16,37,68).HVEM receptor activity is limited to wild-type HSV-1 and HSV-2, whereas nectin-1 acts as a receptor for many alphaherpesviruses (HSV-1, HSV-2, pseudorabies virus [PRV], and bovine herpesvirus 1) (13,23,43,45,47,73). The related nectin-2 can be used only by HSV strains carrying specific mutations in the N-terminal part of gD and by HSV-2 (36, 72). Nectin-3 and nectin-4 are not receptors for herpesviruses, but the related human poliovirus receptor (PVR/CD155) can be used by animal herpesviruses such as PRV and bovine herpesvirus 1 (23,55,56,59).Nectins are widely expressed in tissues and cells (10,16,23,25,37,40,57), where...

RETRACTED: The herpesvirus glycoproteins B and H·L are sequentially recruited to the receptor-bound gD to effect membrane fusion at virus entry

“…Second, there is considerable evidence that expression of gD causes a reduced availability of receptor in transfected cells (39), a ref lection of a key function of gD that prevents reentry of newly released progeny viruses into the cells from which they have emerged (40,41). Consonant with these observations, Krummenacher et al (37) reported downmodulation of nectin1 from the surface of infected cells. Moreover, they reported that in the first 1 h of infection, nectin 1 is modified such that it no longer reacts with an Ab directed to the gD-binding site on nectin 1, even though the total amount of nectin 1 on cell surface remains unchanged (38).…”

“…The kinetics of complex formation is very rapid, about 15 min, and the lifespan of the complex is short, between 15 and 30 min. Although no complex other than that of gD and its receptor was detected in earlier works, these results are in accordance with a number of previous findings, especially with the notion that fusion of herpes simplex virions with cells takes place a few minutes after virus attachment, that virion gD formed a complex with nectin 1 within minutes after virus exposure to cells, that nectin 1 was not removed from the cell surface but was modified during the first 30 min of HSV infection, and that this was followed by relocation of nectin 1 from cell-cell contact areas between 1 and 3 h postinfection (10,(36)(37)(38).…”

Binding of herpes simplex virus glycoprotein D to nectin-1 exploits host cell adhesion

“…Th e intimate interaction between HSV-1 gD and nectin-1 has been observed both in vitro and in vivo 22,28 . In several previous studies using eukaryotic cell expressed gD and nectin-1, the binding affi nity of the two proteins has been demonstrated to be in the twodigit nanomolar range (38 -70 nM) 13,25,29 .…”

“…In this manner the virus escapes from the immune surveillance and in some cases, like HSV, persists into latency. In addition to its initial role in virus initial entry, it has been shown that binding of the HSV-1 surface envelope protein gD to CAMs molecule nectin-1 in infected cells would assist the virus to spread to uninfected cells 24,28,31 . Herein, through complex crystallography, the binding mode of HSV-1 gD with its second receptor nectin-1 is clearly unveiled for the fi rst time.…”

Actin and Rho GTPases in herpesvirus biology

“…Because alphaherpesvirus spread in polarized cells occurs through adherens junctions [62] and because afadin binding is required for nectin-1 to localize at cadherin-based adherens junctions [63], afadin might have a role in viral cell-to-cell spread by directing the gD receptor to the required cellular site in specific cell types. However, a role for the actin-binding properties of nectin during alphaherpesvirus spread seems to be cell-type dependent [64].…”