Humanization of an anti-CD34 monoclonal antibody by complementarity-determining region grafting based on computer-assisted molecular modelling.
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.
Hou
Sheng
S
International Joint Cancer Institute, Second Military Medical University, Shanghai 200433, People's Republic of China.
Li
Bohua
B
Wang
Ling
L
Qian
Weizhu
W
Zhang
Dapeng
D
Hong
Xueyu
X
Wang
Hao
H
Guo
Yajun
Y
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
D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D022801:Complementarity Determining Regions