Selection of an affinity-matured antibody against a defined epitope by phage display of an immune antibody library

• Published in: Journal of immunological methods 2008-01, Vol.329 (1-2), p.176-183
• Main Authors: Kim, Sang Jick, Jang, Myeong Hee, Ahn, Hyun Joo, Kim, Jin Hong, Lim, Ji Hye, Ryu, Chun Jeih, Lim, Nam-Kyu, Kim, Keun-Soo, Park, Mi-Ju, Park, Insoo, Hong, Hyo Jeong
• Format: Article
• Language: English
• Subjects: Affinity maturation; Animals; Antibodies, Monoclonal - biosynthesis; Antibodies, Monoclonal - genetics; Antibodies, Monoclonal - isolation & purification; Antibody Affinity; Antibody Specificity; Binding Sites, Antibody; Biological and medical sciences; Epitope tag; Epitopes; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Hepatitis B Surface Antigens - immunology; Hepatitis B Surface Antigens - metabolism; Hepatitis B virus; Hepatitis B virus - immunology; Hepatitis B virus - metabolism; Hepatitis B virus preS1; Humans; Immunoglobulin Fab Fragments - biosynthesis; Immunoglobulin Fab Fragments - genetics; Immunoglobulin Fab Fragments - isolation & purification; Mice; Mice, Inbred BALB C; Microbiology; Molecular immunology; Monoclonal antibody; Peptide Library; Phage display; Protein Precursors - immunology; Protein Precursors - metabolism; Recombinant Fusion Proteins - immunology; Techniques; Techniques used in virology; Thrombopoietin - immunology; Virology
• ISSN: 0022-1759; 1872-7905
• DOI: 10.1016/j.jim.2007.10.009

In a previous study, we generated a murine hepatitis B virus (HBV)-neutralizing monoclonal antibody (mAb), KR127, that binds to an epitope (amino acids 37–45, NSNNPDWDF) of the preS1 antigen. Furthermore, an epitope tag, S1 (NANNPDWDF), was developed for protein tagging. The aim of the present study was to develop a high-affinity antibody to the same preS1 epitope. Mice were immunized with the N-terminal domain of human thrombopoietin fused to the S1 tag (nTPO-S1), and a phage-displayed chimeric Fab library was constructed and screened by panning against nTPO-S1. A high-affinity antibody (3–34) was selected that binds to the preS1 antigen. The IgG molecules of 3–34 showed approximately nine-fold higher affinity (KD 1.2 nM) for preS1 compared with KR127 (KD 10.4 nM), competed with KR127 for binding to the epitope, and bound to HBV particles. This study provides a simple and efficient way to develop a high-affinity antibody to a defined epitope by phage display of an immune antibody library.