Selection by phage display of nanobodies directed against hypoxia inducible factor‐1α (HIF‐1α)

Abstract

Hypoxia, which promotes tumor invasion and metastasis, is a common phenomenon in solid tumors. Hypoxia generally leads to a higher expression level of hypoxia inducible factor-1 (HIF-1) in tumors (cells) relative to normal tissues (cells). Given the unique expression of HIF-1α in human cancers and its vital importance in mediating hypoxic adaptation, we have identified 20 different HIF-1α-specific nanobodies by using a llama-derived nonimmune phage display library. PAS-B domain of HIF-1α (HIF-1α-PAS-B) has been used as an antigen. Nanobody (VHH16) was selected from these 20 nanobodies by phage enzyme-linked immunosorbent assay. The preliminary analysis of biological activity demonstrates that VHH16 can specifically bind to HIF-1α with high affinity. VHH16 is the first nanobody that specifically binds to HIF-1α-PAS-B as well. We suggest here that VHH16 is useful in disease diagnosis and also has potential in medical applications.

Advances and challenges in targeting IRF5, a key regulator of inflammation

“…There is overwhelming evidence that IRF5 plays a key role in physiology and disease, therefore dampening or enhancing IRF5 expression and activity provides new avenues for the development of therapeutic agents. Among the three strategies for modulation of IRF5 activity and expression discussed in this review, that is, (a) modulating IRF5 expression, (b) interfering with the post-translational modifications of IRF5, and (c) interfering with IRF5 association with protein partners, the modulation of IRF5 levels using siRNA, CRISPR/Cas9, LNAs or perhaps nanobodies, singledomain antibody fragments derived from camelid heavy-chain antibodies that have been successfully utilized to target transcription factors [96][97][98], and adenoviruses, may take a long path in the development of new therapies themselves, but provide excellent opportunities for the identification of new points for therapeutic interference.…”

Research progress and applications of nanobody in human infectious diseases

“…These unique structures provide them with high solubility and good stability under extreme pH or temperature. These structures are beneficial to drug conservation and delivery and offer the possibility of oral or nasal drug uptake routes for nanobodies (Dumoulin et al, 2002;Li et al, 2015;Omidfar and Daneshpour, 2015). The immunogenicity of antibodies may cause serious side effects in vivo, especially when they are used in high doses or large amounts.…”

Moderating hypoxia and promoting immunogenic photodynamic therapy by HER-2 nanobody conjugate nanoparticles for ovarian cancer treatment

“…The insufficient blood supply inside the tumor and the massive oxygen consumption for tumor cell proliferation supports the formation of a hypoxic microenvironment in the tumor and affects performance of the ovarian cancer treatment [39,40]. An existing study demonstrated the ability of HIF-1α-specific nanobody (VHH16) to specifically bind to HIF-1α to further mediate hypoxic adaptation, suggesting its potential for clinical application [41]. Since the hypoxic cancer cells typically contain high H 2 O 2 concentrations, water-soluble CAT is used for conversion of intracellular H 2 O 2 to O 2 [35].…”