Robust humoral and cellular immune responses induced by novel DNA vaccine against West Nile virusin in mice / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To evaluate the immunological efficacy of a novel DNA vaccine against West Nile virus (WNV) in a mouse model.Methods:A DNA vaccine VRC-prME expressing the precursor membrane (prM) and envelope protein (E) of WNV Xinjiang strain (XJ11129-3) was constructed and its ability to express virus-like particles was verified in vitro. C57BL/6 mice were immunized twice with VRC-prME via intramuscular injection combined with electroporation with an interval of four weeks. Enzyme-linked immunoassay (ELISA) was used to detect serum antibodies after immunization. WNV (NY99 strain) single-round infectious particles were used to detect neutralizing antibodies. Cellular immune responses were analyzed by enzyme-linked immunoblot assay (ELISPOT) and intracellular cytokine staining (ICS). Results:VRC-prME induced a strong Th1-biased antibody response in mice that could cross-neutralize the WNV (NY99 strain) single-round infectious particles two weeks after the boost immunization. Moreover, the vaccine also elicited antigen-specific multifunctional CD8 + T cell responses (IFN-γ, IL-2, TNF-α). Conclusions:The novel DNA vaccine prepared in this study, expressing the prME protein of WNV XJ11129-3 strain, could induce stronger humoral and cellular immune responses in mice, which was worthy of further research and development for the prevention of WNV infection in China.