Q493K and Q498H substitutions in Spike promote adaptation of SARS-CoV-2 in mice
Kun Huang,
Yufei Zhang,
Xianfeng Hui,
Ya Zhao,
Wenxiao Gong,
Ting Wang,
Shaoran Zhang,
Yong Yang,
Fei Deng,
Qiang Zhang,
Xi Chen,
Ying Yang,
Xiaomei Sun,
Huanchun Chen,
Yizhi J. Tao,
Zhong Zou,
Meilin Jin
Affiliations
Kun Huang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Yufei Zhang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Xianfeng Hui
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Ya Zhao
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Wenxiao Gong
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Ting Wang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Shaoran Zhang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
Yong Yang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Fei Deng
State Key Laboratory of Virology and National Virus Resource Center, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
Qiang Zhang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Xi Chen
College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China
Ying Yang
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Xiaomei Sun
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China
Huanchun Chen
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China
Yizhi J. Tao
Department of BioSciences, Rice University, Houston, TX 77005, USA
Zhong Zou
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China; Corresponding authors.
Meilin Jin
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, PR China; Corresponding authors.
Background: An ideal animal model to study SARS-coronavirus 2 (SARS-CoV-2) pathogenesis and evaluate therapies and vaccines should reproduce SARS-CoV-2 infection and recapitulate lung disease like those seen in humans. The angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS-CoV-2, but mice are resistant to the infection because their ACE2 is incompatible with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein . Methods: SARS-CoV-2 was passaged in BALB/c mice to obtain mouse-adapted virus strain. Complete genome deep sequencing of different generations of viruses was performed to characterize the dynamics of the adaptive mutations in SARS-CoV-2. Indirect immunofluorescence analysis and Biolayer interferometry experiments determined the binding affinity of mouse-adapted SARS-CoV-2 WBP-1 RBD to mouse ACE2 and human ACE2. Finally, we tested whether TLR7/8 agonist Resiquimod (R848) could also inhibit the replication of WBP-1 in the mouse model. Findings: The mouse-adapted strain WBP-1 showed increased infectivity in BALB/c mice and led to severe interstitial pneumonia. We characterized the dynamics of the adaptive mutations in SARS-CoV-2 and demonstrated that Q493K and Q498H in RBD significantly increased its binding affinity towards mouse ACE2. Additionally, the study tentatively found that the TLR7/8 agonist Resiquimod was able to protect mice against WBP-1 challenge. Therefore, this mouse-adapted strain is a useful tool to investigate COVID-19 and develop new therapies. Interpretation: We found for the first time that the Q493K and Q498H mutations in the RBD of WBP-1 enhanced its interactive affinities with mACE2. The mouse-adapted SARS-CoV-2 provides a valuable tool for the evaluation of novel antiviral and vaccine strategies. This study also tentatively verified the antiviral activity of TLR7/8 agonist Resiquimod against SARS-CoV-2 in vitro and in vivo. Funding: This research was funded by the National Key Research and Development Program of China (2020YFC0845600) and Emergency Science and Technology Project of Hubei Province (2020FCA046) and Robert A. Welch Foundation (C-1565).
