INDUCTION OF NEUTRALIZING ANTIBODIES BY VARICELLA-ZOSTER VIRUS GPII GLYCOPROTEIN EXPRESSED FROM RECOMBINANT VACCINIA VIRUS

The gpII glycoprotein of varicella-zoster virus (VZV) was produced in CV1 cells via vaccinia virus recombinants. Two different DNA constructs were expressed: the first one encodes the complete gpII protein (gpII s+a+) and the second a truncated species lacking the membrane anchorage domain (gpII s+a-). To achieve expression both coding sequences had to be engineered at the 5' end by substituting the unusually short (24 bp) natural signal sequence by a more conventional one encoding 29 amino acids. Recombinant gpII proteins were detected in vaccinia virus-infected cells by ELISA and immunoprecipitation. Both forms of recombinant gpII proteins were produced as glycosylated single-chain molecules of respectively 110K and 90K. Upon reduction these were only partially converted into subunits. A rabbit infected with the vaccinia virus recombinant expressing the complete gpII produced antibodies which recognized VZV antigens and neutralized VZV infectivity in vitro, independent of complement.