Guided selection of human antibody light chains against TAG-72 using a phage display chain shuffling approach.
To enhance therapeutic potential of murine monoclonal antibody, humanization by CDR grafting is usually used to reduce immunogenic mouse residues. Most humanized antibodies still have mouse residues critical for antigen binding, but the mouse residues may evoke immune responses in humans. Previously, we constructed a new humanized version (AKA) of mouse CC49 antibody specific for tumor-associated glycoprotein, TAG-72. In this study, to select a completely human antibody light chain against TAG-72, guided selection strategy using phage display was used. The heavy chain variable region (VH) of AKA was used to guide the selection of a human TAG-72-specific light chain variable region (VL) from a human VL repertoire constructed from human PBL. Most of the selected VLs were identified to be originated from the members of the human germline VK1 family, whereas the VL of AKA is more homologous to the VK4 family. Competition binding assay of the selected Fabs with mouse CC49 suggested that the epitopes of the Fabs overlap with that of CC49. In addition, they showed better antigen-binding affinity compared to parental AKA. The selected human VLs may be used to guide the selection of human VHs to get completely human anti-TAG72 antibody.
Kim
Sang Jick
SJ
Therapeutic Antibody Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejon, Republic of Korea.
Hong
Hyo Jeong
HJ
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D019556:COS Cells; D002522:Chlorocebus aethiops; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology / Q000378:metabolism; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D019151:Peptide Library; D011485:Protein Binding
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D006023:Glycoproteins; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D019151:Peptide Library; C047052:tumor-associated antigen 72