Varicella-zoster virus envelope glycoproteins: biochemical characterization and identification in clinical material

Varicella-zoster virus (VZV)-infected human foreskin fibroblasts synthesize viral glycoproteins of 125,000 (gp125), 118,000 (gp118), 92,000 (gp92), 63,000 (gp63), 59,000 (gp59), and 47,000 (gp47) Da. In biochemical studies, all of these VZV glycoproteins were shown to contain asparagine-linked (N-linked) oligosaccharide chains and, except for gp125 and gp47, to be sialoglycoproteins. Experiments with endo-beta-N-acetylglucosaminidase H (endo H) demonstrated that gp92 contained only complex type (endo H-resistant) N-linked glycosyl chains, while the other mature glycoproteins contained both high-mannose (endo H-sensitive) and complex-type oligosaccharides. Monoclonal antibodies recognizing multiple glycoproteins, gp63/gp125 or gp92/gp59/gp47, neutralized virus infection, suggesting the glycoproteins were important components of the virus envelope. This was confirmed for gp92/gp59/gp47 by immunoelectron microscopy, which revealed dense staining localized exclusively to the virion envelope and to the plasma membrane of virus-producer cells. The mature forms of all of these glycoproteins were also present in viral material isolated from vesicles of varicella and zoster patients, indicating that in infected individuals the viral glycoproteins are synthesized and processed in a manner similar to that in tissue culture cells.