Generation and characterization of a nanobody against the avian influenza virus H7 subtype

Xiuqin Huang; Weiye Li; Xuewei Cao; Qi Zhang; Yizhen Lin; Siqi Xu; Xinying Dong; Peiqi Liu; Yutong Liu; Ge He; Kaijian Luo; Saixiang Feng

doi:10.1016/j.ijbiomac.2024.131458

Generation and characterization of a nanobody against the avian influenza virus H7 subtype

Int J Biol Macromol. 2024 Apr 7;267(Pt 2):131458. doi: 10.1016/j.ijbiomac.2024.131458. Online ahead of print.

Authors

Xiuqin Huang¹, Weiye Li¹, Xuewei Cao¹, Qi Zhang¹, Yizhen Lin¹, Siqi Xu¹, Xinying Dong¹, Peiqi Liu¹, Yutong Liu¹, Ge He¹, Kaijian Luo², Saixiang Feng³

Affiliations

¹ College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
² College of Veterinary Medicine, South China Agricultural University, Guangzhou, China. Electronic address: kjluo@scau.edu.cn.
³ College of Veterinary Medicine, South China Agricultural University, Guangzhou, China. Electronic address: fengsx@scau.edu.cn.

PMID: 38593899
DOI: 10.1016/j.ijbiomac.2024.131458

Abstract

Avian influenza virus (AIV) H7N9 diseases have been recently reported, raising concerns about a potential pandemic. Thus, there is an urgent need for effective therapeutics for AIV H7N9 infections. Herein, camelid immunization and yeast two-hybrid techniques were used to identify potent neutralizing nanobodies (Nbs) targeting the H7 subtype hemagglutinin. First, we evaluated the binding specificity and hemagglutination inhibition activity of the screened Nbs against the H7 subtype hemagglutinin. Nb-Z77, with high hemagglutination inhibition activity was selected from the screened Nbs to optimize the yeast expression conditions and construct oligomeric forms of Nb-Z77 using various ligation methods. The oligomers Nb-Z77-Di_GS, Nb-Z77-Tri_GS, Nb-Z77-Fc and Nb-Z77-Foldon were successfully constructed and expressed. Nb-Z77-Di_GS and Nb-Z77-Foldon exhibited considerably greater activity than did Nb-Z77 against H7 subtype hemagglutinin, with median effective concentrations of 384.7 and 27.33 pM and binding affinity values of 213 and 5.21 pM, respectively. Nb-Z77-Di_GS and Nb-Z77-Foldon completely inhibited the hemagglutination activity of the inactivated virus H7-Re1 at the lowest concentration of 0.938 μg/mL. This study screened a strain of Nb with high hemagglutination inhibition activity and enhanced its antiviral activity through oligomerization, which may have great potential for developing effective agents for the prevention, diagnosis, and treatment of AIV H7 subtype infection.

Keywords: Avian influenza virus; Hemagglutinin; Nanobodies.