SBIR-STTR Award

Recently it has been demonstrated that baculoviruses can be used as high efficiency eukaryotic cloning and expression vectors for the production of foreign proteins. We propose to demonstrate the feasibility and benefits of using the baculovirus expression system for production of subunit vaccines. This demonstration will be exemplified by the expression of the hbsag-gene in insect cells infected with recombinant baculovirus. Special attention will be paid to the time involved and cost-effectiveness of obtaining the final product. This demonstration will involve the following tasks: construction of a recombinant baculovirus which contains the coding sequence for hepatitis b virus surface antigen (hgsag) under the control of a baculovirus polyhedrin-gene promoter. Biochemical and immunological characterization of the hbsag generated by recombinant virus in infected invertebrate tissue culture cells and cell media. Analysis of stability of recombinant virus during several virus genereations. Pilot study of scaled up production in spinner flasks.

Having demonstrated the utility of the baculovirus expression system, we propose to use it to design subunit vaccines to protect against diseases of interest to the military. We have chosen to produce proteins that have the potential to elicit a protective immunity to certain flaviviruses, specifically, japanese encephalitis virus and dengue virus. We propose to construct four recombinant baculoviruses which express the e and nsl genes of both of these viruses. A major factor in choosing to work with this group of viruses is that their life cycle includes mosquito vectors. Since the baculovirus expression system is an insect system, it may be ideally suited for expression of genes of invertebrate origin where other expression systems have been known to fail.