earticle

영어

The pro-apoptotic molecule death receptor 5 (DR5) is an attractive molecule for targeting agonistic monoclonal antibodies because of their inducing tumor specific cell death with little cytotoxicity in normal cell. In previously study, we obtained anti-DR5 human scFv HW1, which induces autophagic cell death in TRAIL-sensitive and –resistant cancer cells without cytotoxicity in normal cell. In this study, to improve agonistic activity of HW1 scFv without epitope change, we constructed HW1 mutant libraries by CDR randomization for affinity enhancement. Using spiked oligonucleotides, these theoretical retention rate levels of target residue 16% to 51%. Affinity maturated HW1A4 scFv increased the affinity was measured 20-fold than HW1. Also affinity maturated CDR grafted into stable human framework (VH3-Vk1), thermodynamic stability of engineered AU12 scFv was significantly improved. Affinity and stability engineered AU12 scFv from HW1 showed enhancement cell death activity in TRAIL-sensitive and –resistant cancer cell line and DR5 specific binding activity without changes of biochemical and biological specificity. These results suggest that affinity and stability improvement correlates their agonistic activity of cell death signaling through DR5.