title: Affinity maturation of an anti-hepatitis B virus PreS1 humanized antibody by phage display.
abstract: In a previous study we generated an anti-Hepatitis B Virus (HBV) preS1 humanized antibody (HzKR127) that showed in vivo HBV-neutralizing activity in chimpanzees. However, the antigen-binding affinity of the humanized antibody may not be sufficient for clinical use and thus affinity maturation is required for better therapeutic efficacy. In this study, phage display technique was employed to increase the affinity of HzKR127. All six amino acid residues (Glu95-Tyr96-Asp97-Glu98-Ala99-Tyr100) in the heavy (H) chain complementarydetermining region 3 (HCDR3) of HzKR127 were randomized and phage-displayed single chain Fv (scFv) library was constructed. After three rounds of panning, 12 different clones exhibiting higher antigen-binding activity than the wild type ScFv were selected and their antigen-binding specificity for the preS1 confirmed. Subsequently, five ScFv clones were converted to whole IgG and subjected to affinity determination. The results showed that two clones (B3 and A19) exhibited an approximately 6 fold higher affinities than that of HzKR127. The affinity-matured humanized antibodies may be useful in anti-HBV immunotherapy.
authors.affiliation: Therapeutic Antibody Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejon, Republic of Korea.
authors.forename: Gi-Hyeok
authors.initials: GH
authors.lastname: Yang
authors.forename: Sun Ok
authors.initials: SO
authors.lastname: Yoon
authors.forename: Myung Hee
authors.initials: MH
authors.lastname: Jang
authors.forename: Hyo Jeong
authors.initials: HJ
authors.lastname: Hong
mesh_terms: D000595:Amino Acid Sequence; D000915:Antibody Affinity / Q000276:immunology*; D000918:Antibody Specificity; D001483:Base Sequence; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors / Q000235:genetics; D006510:Hepatitis B Antibodies / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D019151:Peptide Library; D011498:Protein Precursors / Q000235:genetics / Q000276:immunology*
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D019151:Peptide Library; D011498:Protein Precursors; C050806:presurface protein 1, hepatitis B surface antigen