Expression and analysis of a non-glycosylated varicella-zoster virus subunit vaccine

Includes bibliographical references (pages [42]-46)Varicella-zoster virus (VZV) encodes at least five glycoproteins designated gpl, gpn, gpm, gpIV, and gpV. gpl is encoded by gene 68 and is the most abundant and immunogenic of the VZV glycoproteins. A VZV subunit vaccine, expressing a truncated VZV gpl gene encoding 511 amino acids (TgpI-511) has been developed. Further investigation was carried out to express and analyze a nonglycosylated form of the VZV subunit vaccine. A prokaryotic expression system was utilized to subclone the truncated gene 68, encoding the non-glycosylated subunit vaccine (nTgpI), into the pFUS vector creating the recombinant vector, pFUSl. Protein analysis showed the expression of a fusion protein in Escherichia coli with a size of 70 kDa containing nTgpI (58 kDa) and thioredoxin (th) of 12 kDa. Western blot analysis demonstrated: (1) the reactivity of nTgpI-th with monoclonal antibodies specific for native VZV gpl; and (2) the biological activity of nTgpI-th through its recognition by VZV polyclonal antibodies from a zoster patient. In addition, rabbit immunization of nTgpI-th elicited the production of antibodies which recognized native VZV glycoproteins. These results indicated that the denatured nTgpI-th produced a humoral response in a rabbit which was reactive to native VZV gpl. However, these studies revealed that this prokaryotic expression system was not suitable to produce large quantities of the nTgpI-th vaccine possibly due to the lack of glycosylation of nTgpI-th in E. coli.M.S. (Master of Science