Synthesis and immunogenicity testing of a bioinformatics-predicted B-cell epitope on the Ha antigen from influenza H5N1virus

Abstract

In order to develop vaccine with stable efficiency against easily transforming virus such as influenza H5N1 virus, bioinformatic tools were used to predict conserved epitopes from viral antigens to be used as materials for the development of polyvalent vaccine against this virus. Using this approach, we have successfully predicted one B-cell continuous epitope consisting of 21 amino acids on conserved domains of HA antigen from H5N1 influenza A virus. To confirm the immunogenicity of this epitope, genetic manipulating techniques have been used to prepare the recombinant epitope in E. coli as a fusion form with H:1,2 flagellin antigen from Salmonella Typhimurium and with glutathione S-transferase. This recombinant antigen has been collected, purified and used for immunizing mice. Using ELISA method, we could successfully prove that the anti-recombinant GST-H:1,2-HeBc antibodies could recognize and bind specifically to the HA antigen derived from an influenza H5N1 virus strain isolated from infected chickens in Vietnam in the same way as did the antiserum from mice immunized with commercial inactived H5N1 influenza vaccine.