The immunological effect of Ad/MDC-VP1 combined with DNA vaccine against Coxsackievirus infection / 中华微生物学和免疫学杂志

ABSTRACT

Objective To construct recombinant adenovirus Ad/MDC-VP1 and investigate its im-muno-boosting effect of the mice primed with the experimental DNA vaccine against Coxsackievirus infection. Methods The recombinant adenovirus Ad/MDC-VP1 was constructed and packaged. The Western blot analysis was used to verify the target protein. BALB/c mice were divided into four groups Ad/MDC-VP1 group, pcDNA3/MDC-VP1 group, pcDNA3/MDC-VP1 prime-Ad/MDC-VP1 boost group and PBS group. The mice in each group were immunized intramuscularly. The titers of serum IgG and neutralizing antibody were tested by ELISA and trace neutralization assay, respectively. The lymphocytes proliferation activity and specific CTL cytotoxic activity were tested by CCK-8 assay. The mice in each group were challenged with le-thal dose of Coxsackievirus, and the assay of the serum virus titers and the observation of protection efficacy against Coxsackievirus infection were carried out. Results The recombinant adenovirus Ad/MDC-VP1 was successfully constructed and the target protein was expressed. It was observed that the titers of CVB3 VP1 specific antibody, lymphocyte stimulation index, CTL cytotoxicity activities and protection rate of the pcDNA3/MDC-VP1 prime-Ad/MDC-VP1 boost group were much higher than those of the rest groups( P < 0.05), and the titer of serum virus was lower after CVB3 challenged ( P < 0.05 ). Conclusion Both the cellular and humoral immune responses in mice could been significantly enhanced by the pcDNA3/MDC-VP1 prime-Ad/MDC-VP1 boost strategy.