Administration of DNA and protein vaccines containing gD genes of HSV1 and 2

Abstract number: P1589

Soleimanjahi H., Fotouhi F.

Objectives: Herpes simplex virus type 1&2 infect mucocutaneously and causes oralabial and genital infection in humans, followed by the establishment of a latent infection in the sensory ganglia and can reactivate for life. The prevalence are increasing worldwide and varies widely with generally higher rate in developing than developed countries.

A need for effective vaccine remains the preferred strategy for control of HSV infections.

Methods: The PCR amplified HSV gDs were cloned into desired plasmids in order to construct DNA vaccine or recombinant expression vector. Confirmed baculovirus-based recombinant plasmids were transfected into Sf9 cells, cultured in serum-free Grace's medium at 27^°C and monitored daily for observation of cytopathic effects. After 72 hours, the recombinant baculoviruses were harvested from the cell culture medium. The viral stock was amplified by re-infecting insect cells and titrated as pfu. The Sf9 cells were infected with gDs-baculovirus and incubated at 27^°C for various times to express the recombinant protein of interest.

Results: The constructs were confirmed by colony PCR, Restriction Enzyme Analysis and sequencing. The protein productions in Cos-7 and insect cells were shown by western blot analysis. The recombinant plasmids and protein of interest were injected in different groups of BALB/c mice. The expression vector without any fragment and Sf9 cells were used as negative control and injected to control groups. The inductions of humoral and cellular responses were evaluated.

Conclusion: Although vaccination of mice with a plasmid expressing the neutralising antigens induced humoral and cellular immune responses, but the antibody titer were significantly lower than that of antibodies induced by the subunit protein vaccines. Furthermore, the plasmid DNA as well as recombinant protein vaccine could protect the mice against HSV-1 and HSV-2 lethal challenge.