[Preparation and identification of neutralizing antibodies to envelope protein domain III(ED III) of the four dengue virus serotypes].

Objective To prepare neutralizing monoclonal antibodies (mAbs) against envelope protein domain III of the four dengue virus serotypes (DENV-EDIII) and identify its specificity. Methods BALB/c mice were immunized with recombinant EDIII protein (rDENV-EDIII) of the four DENV serotypes. Hybridoma cells secreting DENV-EDIII antibodies were screened by indirect ELISA. The specificity of positive hybridoma cells were further tested by indirect immunofluorescence assay (IFA). The neutralizing activities of DENV-EDIII mAbs in vitro were determined by the enzyme-linked immunospot microneutralization test (ELISPOT-MNT). Results 6 mAbs specific for the EDIII of the four DENV serotypes and 11 mAbs specific for only one serotype of DENV-EDIII protein were obtained, of which one monoclonal antibody had a balanced strong neutralizing activity against the four DENV serotypes in vitro, and its 50% inhibitory concentrations (IC50) for the four DENV serotypes was 0.05 μg/mL, 1.89 μg/mL, 0.02 μg/mL, 3.91 μg/mL, respectively. Conclusion A specific monoclonal antibody against DENV-EDIII is successfully screened and obtained to neutralize the four DENV serotypes.