Inhibition of VEGF-dependent Angiogenesis and Tumor Angiogenesis by an Optimized Antibody Targeting CLEC14a

Kim TK, et al. , doi: 10.1002/1878-0261.12169, Mol Oncol., 2018

C-type lectin-like 14a (CLEC14a) is a type I transmembrane glycoprotein that has an extracellular domain (ECD). C-type lectin-like domain (CTLD) of ECD is known to play a key role in the mediation of endothelial cell-cell contacts in angiogenesis. Reported herein is the development of a novel anti-angiogenic human monoclonal antibody that specifically targets CLEC14a-CTLD using complementarity-determining region grafting, consecutive deglycosylation, and functional isolation. Newly generated antibody demonstrates improved stability and homogeneity compared to its parental antibody. Furthermore, various in vitro and in vivo functional assays were used to demonstrate that this novel antibody effectively inhibits vascular endothelial growth factor (VEGF)-dependent angiogenesis and tumor angiogenesis. The antibody-antigen interactions were studied using Bio-Layer Interferometry (BLI). A Pall ForteBio Octet RED96 platform equipped with Amine Reactive 2G (AR2G) Biosensor probes was used to perform BLI assays. AR2G sensor tips were immobilized with hCLEC14-ECD. Subsequently, hCLEC14-ECD loaded sensor tips were dipped into two-fold serially diluted Deglyco C1 IgG samples. BLI data were analyzed by fitting to a 1:1 binding model. Association rate constants, dissociation rate constants, and the equilibrium dissociation constants were determined. Overall results of this study suggest that CLEC14a-CTLD may have important implications as a novel anti-angiogenic target for VEGF-dependent angiogenesis and tumor angiogenesis.

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