Expression and function analysis of dengue virus type 1 to 4 envelope domain Ⅲ recombinant fusion protein

Objecfive To observe the ability of dengue virus type 1-4 envelope domain Ⅲ fusion protein to inhibit virus infection and analyze the neutralizing ability of polyclonal antibodies against rEⅢ.Methods After being connected by linker peptide.EⅢ protein of Dengue virus serotypes 1-4 were expressed in E coli BL21(DE3) then purified.Fusion proteins were verified by Western Blot and ELISA.Rabbits were immunized with fusion proteins to produce anti-rE Ⅲ serum.The activity of anti-rEⅢ serum were detected through indirect immunofluorescence assay test.Inhibition of dengue virus type 1 to 4 infection in BHK-21 cells by rEⅢ fusion protein were tested.Neutralizing activity of anti-rEⅢ serum was analyzed.Results Dengue virus type 1 to 4 envelope domain Ⅲ recombinant fusion protein was expressed in Ecoli BL21 and purified successfully.Then rEⅢ fusion protein and anti-rEⅢ serum were analyzed respectively and rEⅢ fusion protein can effectively inhibit dengue virus type 1 to 4 from infecting BHK cells.The anti-rE Ⅲ serums can neutralize dengue virus type 1 to 4 but with different neutralizing titer.Conclusion Dengue virus type 1-4 envelope domain Ⅲ fusion protein can directly inhibit DV infeetion.Antibodies induced by rE Ⅲ fusion proteins can neutralize dengue virus type 1-4.