title: Humanization of an anti-CD34 monoclonal antibody by complementarity-determining region grafting based on computer-assisted molecular modelling.
abstract: 4C8 is a new mouse anti-human CD34 monoclonal antibody (mAb), which recognizes class II CD34 epitopes and can be used for clinical hematopoietic stem/progenitor cell selection. In an attempt to improve its safety profiles, we have developed a humanized antibody of 4C8 by complementarity-determining region (CDR) grafting method in this study. Using a molecular model of 4C8 built by computer-assisted homology modelling, framework region (FR) residues of potential importance to the antigen binding were identified. A humanized version of 4C8, denoted as h4C8, was generated by transferring these key murine FR residues onto a human antibody framework that was selected based on homology to the mouse antibody framework, together with the mouse CDR residues. The resultant humanized antibody was shown to possess antigen-binding affinity and specificity similar to that of the original murine antibody, suggesting that it might be an alternative to mouse anti-CD34 antibodies routinely used clinically.
authors.affiliation: International Joint Cancer Institute, Second Military Medical University, Shanghai 200433, People's Republic of China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Hou
authors.forename: Bohua
authors.initials: B
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Weizhu
authors.initials: W
authors.lastname: Qian
authors.forename: Dapeng
authors.initials: D
authors.lastname: Zhang
authors.forename: Xueyu
authors.initials: X
authors.lastname: Hong
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Yajun
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D018952:Antigens, CD34 / Q000276:immunology*; D001667:Binding, Competitive; D045744:Cell Line, Tumor; D022801:Complementarity Determining Regions / Q000737:chemistry*; D006801:Humans; D021621:Imaging, Three-Dimensional; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid
chemical_list: D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D022801:Complementarity Determining Regions