A Novel Peptide Isolated from a Phage Display Peptide Library Modeling Antigenic Epitope of DHAV-1 and DHAV-3

Duck hepatitis A virus (DHAV), the major pathogen of duck virus hepatitis (DVH), causes severe diseases that threaten the duck industry worldwide. The VP1 protein, a major structural protein of DHAV, is able to induce neutralizing antibody in ducks. The purpose of this study was to identify the antigenic mimotope of DHAV by phage display technology. A monoclonal antibody (mAb) 4E6 against DHAV-1 and DHAV-3 was prepared, and a phage library prepared with the PhD-12 Phage Display Peptide Library Kit was screened with the mAb. A novel peptide, GLTWKLPPSM was identified with high affinity to the mAb and could specifically block mAb 4E6 from binding DHAV-1 and DHAV-3. Animal tests confirmed that the immunization of ducklings with the mimotope could inhibit the virus proliferation and protect the ducklings from DVH. In summary, the neutralizing conformational mimotope GLTWKLPPSM might be a promising vaccine candidate for the prevention of DHAV infection.