Synthesis and processing of glycoproteins of Varicella-Zoster virus (VZV) as studied with monoclonal antibodies to VZV antigens.

Varicella-Zoster virus (VZV) contains four major glycoproteins designated as gp 1(115K), gp 2(100-80K), gp 3(64K), and gp 5(55K) (K. Shiraki, T. Okuno, K. Yamanishi, and M. Takahashi, J. Gen. Virol. 61, 255-269, 1982). The present studies focused on the synthesis and processing of these glycoproteins using monoclonal antibodies. Twenty-seven hybridomas secreting monoclonal antibodies against VZV proteins have been established. The antibodies were characterized further by radioimmunoprecipitation with [35S]-methionine, [3H]glucosamine, [125I]labeled viral antigens followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Twelve clones of these hybridomas produced antibodies to glycosylated polypeptides of VZV, which could be classified into three groups on the basis of the electrophoretic patterns. The first group reacted specifically with polypeptides with apparent molecular weights of 94K and 83K (both presumed to correspond to gp 2) in infected cells, on the surface membrane of infected cells, and on the virions. The second group precipiated polypeptides with molecular weights of 94K, 83K, 55K (corresponding to gp 5) in infected cells, and 94K, 83K, 55K, 45K on the surface membrane of infected cells, and 94K, 83K, and 55K on the virions. Finally, the third group reacted with polypeptides with molecular weights of 116K, 106K, and 64K corresponding to gp 3) in infected cells, 64K on the surface membrane of infected cells, and on the virions. By pulse-chase experiments, antibodies from the former two groups precipitated new polypeptides with molecular weights of 75K and 49K, respectively, which were presumed to be precursor proteins. These data suggest that the precursor proteins of gp 2, gp 3, and gp 5 are synthesized in infected cells, glycosylated, and the product proteins are expressed on the surface membrane of infected cells as well as on the virions. It was also found that a glycoprotein of 45K detected in culture fluid of infected cells (K. Shiraki and M. Takahashi, J. Gen. Virol. 61, 271-275, 1982) was derived from the polypeptide with molecular weight of 55K (gp 5).