A Recombinant Monospecific Anti‑PLGF Bivalent Nanobody for Angiogenesis Targeting

Background and Objective: During the past two decades, tumor therapy based on monoclonal antibody has been found as a confident therapeutic approach in solid tumors and hematologic malignancies. Nanobodies are the smallest fragment of an antigen-binding domain in heavy chain-only antibody originated from the Camelidae family. Accordingly, they are being recently developed rapidly as diagnostic and therapeutic agents. In this regard, targeting of angiogenic factors like Placenta growth factor (PLGF) via nanobodies show a high effectiveness.Materials and Methods: In the current study, we developed a recombinant anti-PLGF bivalent nanobody based on the affinity enhancement mutant form of anti-PLGF nanobody to suppress the angiogenesis progression. Thereafter, the bivalent nanobody (bi-Nb) was cloned and then expressed into a bacterial system. Afterward, the purity was authorized using western blot assay and the affinity was assessed using ELISA. In this regard, proliferation, ۳D capillary tube formation, and migration assays were employed as functional assays. The obtained data were analyzed using t-test and P < ۰.۰۵ was considered as statistically significant Findings: The results indicated that the bivalent nanobody could inhibit proliferation, mobility, and formation of endothelial cell capillary-like structure. Moreover, the EC۵۰ was estimated for endothelial cell proliferation and capillary tube formation to be about ۱۰۰ ng/ml and ۶۵ ng/ml, respectively. Migration of MCF-۷ was inhibited as about ۶۹%, rather than the control. Conclusion: Accumulation of data have shown that targeting of angiogenic factors like VEGF via monoclonal antibodies or nanobodies can be useful in the suppression of tumor progression. Also, the inhibition of PLGF with monoclonal antibody indicated that it is significant in angiogenesis suppression. However, due to the intrinsic properties of nanobodies, they are suggested to be used. Since the small size is rapidly removed through the liver or kidney system, so it is important to use bivalent or polymeric forms for extending the halflife.Our findings indicated that the inhibition of PLGF can prevent the growth and proliferation of endothelial cells and tumor cells through the bivalent nanobody. So, it is suggested as a novel therapeutic agent for angiogenesis suppression.

کلیدواژه ها:

Nanobody ، VHH ، Angiogenesis ، PLGF