Proteomic Analysis To Augmented Immune Responses In Mouse By Prime-and-Boost Immunization Strategy With HBsAg DNA And Protein Vaccine

Prime-and-boost vaccination strategy with DNA and protein vaccines is broadly adopted to augment the immunogenicity of both vaccines, but the mechanism is ambiguous. We constructed the HBsAg-expressing plasmid pVAX-S, and immunized C57BL/6 mice with pVAX-S and recombinant HBsAg by 4 regimes named DDD, DDS, SSS and SSD. Antigen-specific total antibody production was detected using ELISA on 3, 7, 11, 15, 19 and 23 weeks after the first immunization. The intensity of T cell immunological memory and the capacity of DCs to provoke T cells were evaluated employing mixed lymphocyte reactions on week 11. The CTL activity was examined using a colorimetric method on week 23. Stronger immunological memory and DC potency were demonstrated in group DDS (mice immunized with rHBsAg after twice DNA priming), well coincident with the induced higher level of total antibodies and CTL activity. Comparative serum proteomics was employed to investigate the possible mechanisms of immunopotentiation effects. In comparison with proteome of non-vaccinated mice, 5 proteins in group DDS were up-regulated and 17 proteins down-regulated by more than 2.5-fold in quantity, whereas in group SSS (mice immunized thrice with rHBsAg) 7 up-regulated and 10 down-regulated. Periplakin, F-box protein 30 and calpain detected only in group DDS hold definite association with immune responses, which might be potential markers of successful vaccination and provide research targets for molecular mechanism of vaccinology. In an ongoing subject, we immunized mice with annexin B1 DNA or protein then examined the serum proteome of the mice, obtaining 6 specific-expressing proteins identified by mass spectrometry. These 6 proteins are total different from the 6 ones identified from DDS/SSS mice sera, indicating the 3 specific-expressing proteins from DDS mice sera are antigen-specific.