Objective: To construct human metapneumovirus (hMPV) DNA vaccines and evaluate the cellular and humoral immune response in mice.
Methods: Fusion protein FdeltaTM (without transmembrane domain) gene and M gene of hMPV were amplified from cDNA by PCR, then DNA vaccines pcDNA3.1His-FdeltaTM and pcDNA3.1His-M were constructed to verify the expression of F and M protein by Western blotting and indirect immunofluorescent assay (IFA) respectively. Serum IgG and spleen cell CTL were detected with ELISA and ELISPOT assay after the BALB/c mice were immunized intramuscularly with the vaccines.
Results: The candidate DNA vaccines could express FdeltaTM and M protein as detected with Western blotting and IFA. The IgG antibody titers of mice was 1:44 when immunized with pcDNA3.1His-FdeltaTM, but could increase to 1:64 when co-immunized with pcDNA3.1His-M. ELISPOT assay demonstrated that IFN-gamma-secreting effector T cells reached 42 +/- 8.9 in co-immunization group, higher than single vaccine pcDNA3.1His-FdeltaTM group (32 +/- 7.4).
Conclusion: DNA vaccine pcDNA3.1His-FdeltaTM could induce specific cellular and humoral immune responses, and the immune response could increase when co-immunization with pcDNA3.1His-M was carried out.