Generation and characterization of a novel human IgG1 antibody against vascular endothelial growth factor receptor 2

Abstract

VEGF and its receptors, especially VEGFR2 (KDR), are known to play a critical role in angiogen- esis under both physiological and pathological conditions, including cancer and angiogenic retinopathies. This study was aimed at developing a fully human IgG1 antibody (mAb-04) constructed from a phage-derived scFv, target- ing the VEGF/VEGFR2 pathway. Firstly, an innovative transfection system, containing two recombinant expres- sion vectors (pMH3 and pCApuro), were introduced into CHO-s cells and clones with higher yield selected accord- ingly. After an optimal fermentation condition was deter- mined, fed-batch fermentation was performed in 5-L bioreactor with a final yield up to 60 mg/L. Further, cell proliferation, wound healing, transwell invasion, tube for- mation and chick embryo chorioallantoic membrane assays showed significant anti-angiogenic activity of mAb-04 in vitro and in vivo. In addition, the results of Western blot- ting indicated the ability of mAb-04 to inhibit VEGF- induced VEGFR2 signaling pathway. Finally, ADCC assay demonstrated that mAb-04 is capable of mediating tumor cell killing in presence of effector cells. This study has therefore proved that the full-length antibody targeting human VEGFR2 has potential clinical applications in the treatment of cancer and other diseases where pathological angiogenesis is involved.