Effects of various prime-boost regimes on immunities in mice by using DNA and reocmbinant vaccin-ia-based H5N1 vaccines / 中华微生物学和免疫学杂志

ABSTRACT

Objective To develop an effective and broad immune protective vaccination strategy by using DNA and recombinant vaccinia-based H5N1 vaccines.Methods BALB/c mice were immunized with various prime-boost regimens by using different DNA ( pIRES-based or pVRC-based) and recombinant vaccinia (Tiantan strain, rTTV)-based H5N1 vaccines expressing multivalent antigens (HA, NA, M1 and M2).The differences of immunity induced by two DNA vaccines were compared between intradermal electro -poration (IDE) and intramuscular electroporation (IME) deliveries.Immune responses were analyzed by hemagglutination inhibition( HAI) assay, neuraminidase ( NA)-specific antibody measured by ELISA , mi-croneutralization assay and IFN-γELISPOT assay .Results High levels of humoral immunity and T cell re -sponses were induced in mice primed with DNA-based vaccine than those primed with rTTVb-ased vaccine . DNA priming by IDE resulted in higher levels of neutralizing antibody in mice than those by IME delivery . Higher levels of HAI and anti-NA antibodies as well as NA-specific T cell responses were induced by pVRC-based DNA prime than those by pIRES-based DNA prime .HA-specific T cell responses were also enhanced in mice primed with pVRC-based DNA than those primed with pIRES-based DNA by IME .Conclusion The prime-boost strategies by using DNA-based vaccine in combination with rTTV-based H5N1 vaccine could induce humoral and T cell responses in mice against multi-antigens .Immunities induced by vaccines in com-bination might be modulated by various prime regimes .The study provided references for the further develop-ment of novel H5N1 vaccine and the optimization of immunization programs of combined multi-antigen vac-cine candidates .