Abstract
The use of mammalian cells as substrates for the production of various vaccines is a time‐honored procedure. With the advent of recombinant DNA technology, various investigators soon realized that these techniques could be applied to mammalian cells to convert them to reliable, safe producers of a variety of vaccines. While none of these types of recombinant vaccines have, as yet, been widely utilized, many individuals believe that these technologies are the wave of the future in vaccine production. In this paper our work on the use of mammalian cells for the development of subunit vaccines for the prevention of infection by herpes simplex virus (HSV) types 1 and 2 is reviewed. A surface glycoprotein of these viruses, gD, was chosen as a likely candidate for a subunit vaccine based upon its primary sequence conservation between the two viral types as well as upon data suggesting that antibodies against this glycoprotein were highly efficient at neutralizing virus infectivity. Stable mammalian cell lines were constructed that expressed secreted forms of this protein, and the protein could be purified from cell‐conditioned supernatants to near‐homogeneity. Vaccination of mice with this glycoprotein was found to protect them form a lethal intraperitoneal infection by either the type 1 or type 2 forms of this virus. In a more realistic study, guinea pigs vaccinated with either the type 1 or type 2 forms of this virus. In a more realistic study, guinea pigs vaccinated with either the type 1 or type 2 form of gD were found to be protected form a genital form of HSV 2 infection. Finally, analysis of these guinea pigs revealed that the establishment of latency by HSV 2 was also inhibited by vaccination with gD. These preliminary animal studies strongly suggest that gD produced in a recombinant mammalian cell expression system might induce protective immunity in humans vaccinated with this glycoprotein.