Effect of LIGHT Adjuvant on Kinetics of T-Cell Responses Induced by HSV-1 DNA Immunization

Background: Studies on efficacy of various vaccines that prevent or reduce the primary and recurrent HSV-1 infection have demonstrated the importance of cellular immunity for protection against the infection. We previously used DNA vaccination to induce cellular immunity against HSV-1 infection in mice. Objective: The aim of our study was to evaluate the effect of LIGHT, a member of TNF super family, on the kinetic of CTL response induced by HSV-1 glycoprotein B based DNA vaccine. Methods: Using a granzyme B ELISA for detection and analysis of CD8+ T cells, CTL activity was determined in the spleen of BALB/c mice at various time points after primary and booster dose of vaccination. The kinetics of CTL response to primary and secondary HSV-1 infection and DNA vaccination were compared to those induced by DNA vaccination in combination with LIGHT adjuvant in the present study. Results: In primary and secondary immunization, the CTL activity in the HSV injected group peaked 7 days and 12 hours post immunization, respectively. After 5 days, LIGHT could neither accelerate the CTL response compared to DNA vaccination alone nor could enhance the CTL activity in the primary and the first peak of memory response, the amount of granzyme B induced by the LIGHT containing vaccine was significantly higher than that induced by the vaccine without the adjuvant. Conclusion: Although LIGHT enhances the cellular response in the booster dose of vaccination, it does not accelerate the CTL response.