β-Glucan Oligosaccharide EnhancesCD8+T Cells Immune Response Induced by a DNA Vaccine Encoding Hepatitis B Virus Core Antigen

Abstract

DNA vaccination can induce specificCD8+T cell immune response, but the response level is low in large mammals and human beings. Coadministration of an adjuvant can optimize protective immunity elicited by a DNA vaccine. In this study, we investigated the effect of a synthetic glucohexaose (β-glu6), an analogue of Lentinan basic unit, on specificCD8+T cell response induced by a DNA vaccine encoding HBcAg (pB144) in mice. We found thatβ-glu6 promoted the recruitment and maturation of dendritic cells, enhanced the activation ofCD8+andCD4+T cells and increased the number of specificCD8+/IFN-γ+T cells in lymphoid and nonlymphoid tissues in mice immunized by pB144. Immunization with pB144 andβ-glu6 increased the anti-HBc IgG and IgG2a antibody titer. These results demonstrate thatβ-glu6 can enhance the virus-specific CTL and Th1 responses induced by DNA vaccine, suggestingβ-glu6 as a candidate adjuvant in DNA vaccination.