Construction of recombinant eukaryotic plasmids enconding fused envelope domain III s of dengue virus and its immunogenicity in mice.

Objective:To analyze immunogenicity of the fused envelope domain Ⅲs of dengue virus by immunization with DNA vaccine.Methods:Envelope domain Ⅲs of dengue serotypes 1 and 2,3 and 4 were spliced by a linker(Gly-Gly-Ser-Gly-Ser)3 and cloned into eukaryotic vector pCDNA3.1(+)to generate recombinant bivalent plasmids,then transfected into BHK-21 cells.Expression of the recombinant protein was identified by indirect immunofluorescent assay and Western blot.The tetravalent recombinant plasmids were used to the immunize mice to observe their immunogenicity and ability to induce neutralizing antibodies.Results:The results showed that the recombinant protein could be expressed by BHK-21 cells.Mice immunized with tetravalent plasmids were able to produce neutralizing antibodies against dengue virus type 1 to 4,with neutralizing titers 1∶24.7,1∶26.9,1∶13.4 and 1∶16.0 respectively.Conclusion:It is suggested that the recombinant plasmids are valuable for development of a tetravalent DNA vaccine against dengue virus.