1. Affinity-matured variants derived from nimotuzumab keep the original fine specificity and exhibit superior biological activity
- Author
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Yaima Tundidor, Gertrudis Rojas, Stefan Dübel, Lisset Chao, Luis F. Ponce, Joaquín Solozábal, and Michael Hust
- Subjects
0301 basic medicine ,medicine.drug_class ,Molecular biology ,Genetic Vectors ,Immunology ,Antibody Affinity ,Immunoglobulin Variable Region ,lcsh:Medicine ,Monoclonal antibody ,Antibodies, Monoclonal, Humanized ,Transfection ,Biochemistry ,Epitope ,Article ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Immunoglobulin Idiotypes ,Cell Line, Tumor ,Neoplasms ,medicine ,Nimotuzumab ,Humans ,Bacteriophages ,Computer Simulation ,Epidermal growth factor receptor ,lcsh:Science ,Cancer ,Multidisciplinary ,biology ,Chemistry ,Biological techniques ,lcsh:R ,Recombinant Proteins ,Computational biology and bioinformatics ,ErbB Receptors ,030104 developmental biology ,030220 oncology & carcinogenesis ,Monoclonal ,biology.protein ,Paratope ,lcsh:Q ,Antibody ,medicine.drug ,Biotechnology - Abstract
Nimotuzumab is a humanized monoclonal antibody against the Epidermal Growth Factor Receptor with a long history of therapeutic use, recognizing an epitope different from the ones targeted by other antibodies against the same antigen. It is also distinguished by much less toxicity resulting in a better safety profile, which has been attributed to its lower affinity compared to these other antibodies. Nevertheless, the ideal affinity window for optimizing the balance between anti-tumor activity and toxic effects has not been determined. In the current work, the paratope of the phage-displayed nimotuzumab Fab fragment was evolved in vitro to obtain affinity-matured variants. Soft-randomization of heavy chain variable region CDRs and phage selection resulted in mutated variants with improved binding ability. Two recombinant antibodies were constructed using these variable regions, which kept the original fine epitope specificity and showed moderate affinity increases against the target (3-4-fold). Such differences were translated into a greatly enhanced inhibitory capacity upon ligand-induced receptor phosphorylation on tumor cells. The new antibodies, named K4 and K5, are valuable tools to explore the role of affinity in nimotuzumab biological properties, and could be used for applications requiring a fine-tuning of the balance between binding to tumor cells and healthy tissues.
- Published
- 2020