A neutralizing bispecific single-chain antibody against SARS-CoV-2 Omicron variant produced based on CR3022

Kaikai Yu; Bin Liu; Haotian Yu; Chengbiao Sun; Xuefeng Wang; Guorui Li; Mingxin Dong; Yan Wang; Jianxu Zhang; Na Xu; Wensen Liu

doi:10.3389/fcimb.2023.1155293

A neutralizing bispecific single-chain antibody against SARS-CoV-2 Omicron variant produced based on CR3022

Front Cell Infect Microbiol. 2023 May 3:13:1155293. doi: 10.3389/fcimb.2023.1155293. eCollection 2023.

Authors

Kaikai Yu¹, Bin Liu², Haotian Yu¹, Chengbiao Sun¹, Xuefeng Wang¹, Guorui Li³, Mingxin Dong¹, Yan Wang¹, Jianxu Zhang¹, Na Xu⁴, Wensen Liu¹

Affiliations

¹ Changchun Veterinary Research Institute, Chinese Academy of Agricultural Science, Changchun, Jilin, China.
² State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
³ College of Life Sciences and Food Engineering, Inner Mongolia Minzu University, Tongliao, China.
⁴ Academic Affairs Office, Jilin Medical University, Jilin, Jilin, China.

Abstract

Introduction: The constantly mutating SARS-CoV-2 has been infected an increasing number of people, hence the safe and efficacious treatment are urgently needed to combat the COVID-19 pandemic. Currently, neutralizing antibodies (Nabs), targeting the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein are potentially effective therapeutics against COVID-19. As a new form of antibody, bispecific single chain antibodies (BscAbs) can be easily expressed in E. coli and exhibits broad-spectrum antiviral activity.

Methods: In this study, we constructed two BscAbs 16-29, 16-3022 and three single chain variable fragments (scFv) S1-16, S2-29 and S3022 as a comparison to explore their antiviral activity against SARS-CoV-2. The affinity of the five antibodies was characterized by ELISA and SPR and the neutralizing activity of them was analyzed using pseudovirus or authentic virus neutralization assay. Bioinformatics and competitive ELISA methods were used to identify different epitopes on RBD.

Results: Our results revealed the potent neutralizing activity of two BscAbs 16-29 and 16-3022 against SARS-CoV-2 original strain and Omicron variant infection. In addition, we also found that SARS-CoV RBD-targeted scFv S3022 could play a synergistic role with other SARS-CoV-2 RBD-targeted antibodies to enhance neutralizing activity in the form of a BscAb or in cocktail therapies.

Discussion: This innovative approach offers a promising avenue for the development of subsequent antibody therapies against SARSCoV-2. Combining the advantages of cocktails and single-molecule strategies, BscAb therapy has the potential to be developed as an effective immunotherapeutic for clinical use to mitigate the ongoing pandemic.

Keywords: COVID-19; Omicron variant; SARS-CoV-2; bispecific antibody; single-chain variable fragment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antibodies, Monoclonal
Antibodies, Neutralizing
Antibodies, Viral / therapeutic use
Antiviral Agents
COVID-19*
Escherichia coli
Humans
Pandemics
SARS-CoV-2 / genetics
Single-Chain Antibodies* / genetics

Substances

CR3022
spike protein, SARS-CoV-2
Antibodies, Monoclonal
Antibodies, Neutralizing
Single-Chain Antibodies
Antibodies, Viral
Antiviral Agents

Supplementary concepts

SARS-CoV-2 variants

Grants and funding

This work was funded by the National Science and Technology Major Project [grant number 2018ZX10101003-005] and the National Natural Science Foundation of China [grant number 81773630].