The Herpes Simplex Virus gE-gI Complex Facilitates Cell-to-Cell Spread and Binds to Components of Cell Junctions

Abstract

The herpes simplex virus (HSV) glycoprotein complex gE-gI mediates the spread of viruses between adjacent cells, and this property is especially evident for cells that form extensive cell junctions, e.g., epithelial cells, fibroblasts, and neurons. Mutants lacking gE or gI are not compromised in their ability to enter cells as extracellular viruses. Therefore, gE-gI functions specifically in the movement of virus across cell-cell contacts and, as such, provides a molecular handle on this poorly understood process. We expressed gE-gI in human epithelial cells by using replication-defective adenovirus (Ad) vectors. gE-gI accumulated at lateral surfaces of the epithelial cells, colocalizing with the adherens junction protein ␤-catenin but was not found on either the apical or basal plasma membranes and did not colocalize with ZO-1, a component of tight junctions. In subconfluent monolayers, gE-gI was found at cell junctions but was absent from those lateral surfaces not in contact with another cell, as was the case for ␤-catenin. Similar localization of gE-gI to cell junctions was observed in HSV-infected epithelial cells. By contrast, HSV glycoprotein gD, expressed using a recombinant Ad vectors, was found primarily along the apical surfaces of cells, with little or no protein found on the basal or lateral surfaces. Expression of gE-gI without other HSV polypeptides did not cause redistribution of either ZO-1 or ␤-catenin or alter tight-junction functions. Together these results support a model in which gE-gI accumulates at sites of cell-cell contact by interacting with junctional components. We hypothesize that gE-gI mediates transfer of HSV across cell junctions by virtue of these interactions with cell junction components. Jay Nelson, Oregon Health Sciences University) were grown in RPMI medium (BioWhittaker Inc., Walkersville, Md.) supplemented with 10% (vol/vol) heatinactivated fetal bovine serum (FBS; BioWhittaker). 293 cells (17) and Vero cells were grown in Dulbecco's modified minimal essential medium (DMEM; Bio-Whittaker) supplemented with 10 and 5% FBS, respectively. HSV-1 strains F (obtained from P. G. Spear, Northwestern University Medical School, Chicago, Ill.), F-US7kan (25), and F-gE␤ (14) were propagated on, and their titers were determined on, Vero cells. Two replication-competent Ad vectors, AdgE and AdgI, that were described previously (19) will be denoted Ad(E1 ϩ )gE and Ad(E1 ϩ )gI here. Ad(E1 Ϫ )gE, Ad(E1 Ϫ )gI, AdgD1(E1 Ϫ ) (7), and AddlE1, which contains no HSV sequences, are all replication-defective (E1 Ϫ ) Ad vectors, and they were propagated on, and their titers were determined on, 293 cells.Antibodies. Monoclonal antibody (MAb) 3104, specific for gI, and MAb 3114, specific for gE (25), were gifts of Anne Cross and Nigel Stow (Institute of Virology, Glasgow, United Kingdom). MAb II-481, specific for gE, was a gift of Patricia Spear (Northwestern University Medical School). MAb DL-6, specific for gD (22), was a gift of Gary Cohen and Roselyn Eisenberg (University of Pennsylvania, Philadel...

Varicella-Zoster Virus gE Escape Mutant VZV-MSP Exhibits an Accelerated Cell-to-Cell Spread Phenotype in both Infected Cell Cultures and SCID-hu Mice

“…The role of gE in mediating cell-to-cell spread has been well studied in both HSV-1 and PRV (Dingwell et al, 1994(Dingwell et al, , 1995Dingwell and Johnson, 1998;Tirabassi et al, 1997;Wisner et al, 2000;Zsak et al, 1992). Deletional mutants of HSV-1 gE and gI exhibit a reduced plaque size phenotype in tissue culture as well as reduced neuronal spread in a rat eye model (Dingwell et al, 1994;Dingwell and Johnson, 1998). Studies in the PRV system with gE deletional mutants demonstrated a similar reduced spread in tissue culture and a rat eye model (Tirabassi et al, 1997;Zsak et al, 1992).…”

Oncolytic viruses in cancer therapy

“…In addition to facilitating virus spread, syncytiosome formation may be directly toxic to the cells and syncytia are also more readily recognized by the immune system, increasing the tumor-killing capacity of oncolytic viruses even further or confer-ring killing capacity to otherwise apathogenic constructs [64]. Viral genomes may also piggyback on exocytosed vesicles or jump from cell to cell through tight junctions, as has been documented for a variety of different viruses and viral vectors [65][66][67]. Moreover, some vectors may not be based on any specific virus yet still be packaged into VLPs.…”

Insulin Degrading Enzyme Is a Cellular Receptor Mediating Varicella-Zoster Virus Infection and Cell-to-Cell Spread

“…HSV glycoprotein D (gD) has been identified as the viral ligand for each of these receptors. HSV gE/gI, though not essential for entry and replication, sorts nascent virions to cell junctions and is required for efficient cell-to-cell spread of HSV (Collins and Johnson, 2003;Dingwell and Johnson, 1998). Although a cellular receptor for gE/gI has been postulated, it has not yet been identified.…”