Preparation and Identification of a Single-chain Antibody Fragment Against High Pathogenic H5N1 Avian Influenza Virus

Previously, an mAb 10F7 was developed against H5N1 hemagglutinin, which was highly specific to 34 different H5N1 strains and showed good neutralizing activity. In the present study, the single-chain fragment of the antibody was cloned into a prokaryotic vector and then expressed in E. coli. The activity of the scFv was tested in hemagglution inhibition and neutralization experiment. Two H5N1 virus strains were inhibited to bind erythrocyte cells by the scFv while the H9 virus was not. Also, five H5N1 virus strains were neutralized during infecting MDCK cells. These results showed an approachable method for developing therapeutic antibody to H5N1 virus.