Varicella-zoster virus (VZV) is one of the human herpes viruses. It causes chickenpox in childhood; after chickenpox the virus remains in a latent state in the dorsal root ganglia of the spinal cord. When the virus reactivates in late adulthood, it causes the disease known as shingles or herpes zoster. The VZV genome includes approximately 70 open-reading frames, but only a few of the gene products have been well characterized.

The VZV glycoproteins include gH, gL, gE and gI. The gH:gL complex is an important viral fusogen. Through laser scanning confocal microscopy, we developed an assay to measure VZV-induced fusion and syncytial formation. VZV also encodes a cell surface Fc receptor, glycoprotein gE. VZV gE has previously been shown to display several features common to nonviral cell surface receptors. Attention focused on the ability of VZV gE to undergo receptor-mediated endocytosis. The transient transfection studies demonstrated by confocal microscopy and intemalization assays that VZV gE was endocytosed when expressed in HeLa cells. Endocytosis of gE was shown to be dependent on clathrin-coated vesicle formation within the cells.