Abstract
Purpose: To evaluate the immunogenicity and types of immune response of a quality-controlled modified recombinant hepatitis B surface antigen (HBsAg) plasmid encoding HBsAg in mice.
Methods: The characterized plasmid DNA was used in the immunization of Balb/c mice. Three groups of mice were intramuscularly injected with three different concentrations (50, 25 and 10 mu g/100 mu L) of the modified plasmid. Humoral immune response was monitored by enzyme-linked immunosorbent assay (ELISA), while cellular immune response was investigated by analysis of spleen cytokine profile (TNF alpha, IFN gamma and IL2) as well as CD69 expression level in CD4 and CD8 positive cells.
Results: In general, the activated CD4 cells showing intracellular cytokines were higher than CD8 positive population of cells (p < 0.05). These findings indicate that the vaccine induced both a humoral and cellular immunity. Cytokine profile also showed high levels of TNF alpha, IFN gamma and IL2 and CD69 expression in the group of animals immunized at a dose of 10 mu g when compared to control group (p < 0.05).
Conclusion: A 10 mu g dose intramuscular injection of the modified DNA-based vaccine encoding HBsAg in mice induces both high humoral and cellular immune responses.