SARS-CoV-2 Delta and Omicron variants resist spike cleavage by human airway trypsin-like protease

• Text
• PDF

Abstract

Soluble host factors in the upper respiratory tract can serve as the first line of defense against SARS-CoV-2 infection. In this study, we described the identification and function of a human airway trypsin–like protease (HAT), capable of reducing the infectivity of ancestral SARS-CoV-2. Further, in mouse models, HAT analogue expression was upregulated by SARS-CoV-2 infection. The antiviral activity of HAT functioned through the cleavage of the SARS-CoV-2 spike glycoprotein at R682. This cleavage resulted in inhibition of the attachment of ancestral spike proteins to host cells, which inhibited the cell-cell membrane fusion process. Importantly, exogenous addition of HAT notably reduced the infectivity of ancestral SARS-CoV-2 in vivo. However, HAT was ineffective against the Delta variant and most circulating Omicron variants, including the BQ.1.1 and XBB.1.5 subvariants. We demonstrate that the P681R mutation in Delta and P681H mutation in the Omicron variants, adjacent to the R682 cleavage site, contributed to HAT resistance. Our study reports what we believe to be a novel soluble defense factor against SARS-CoV-2 and resistance of its actions in the Delta and Omicron variants.

Authors

Wenyan Ren, Weiqi Hong, Jingyun Yang, Jun Zou, Li Chen, Yanan Zhou, Hong Lei, Aqu Alu, Haiying Que, Yanqiu Gong, Zhenfei Bi, Cai He, Minyang Fu, Dandan Peng, Yun Yang, Wenhai Yu, Cong Tang, Qing Huang, Mengli Yang, Bai Li, Jingmei Li, Junbin Wang, Xuelei Ma, Hongbo Hu, Wei Cheng, Haohao Dong, Jian Lei, Lu Chen, Xikun Zhou, Jiong Li, Wei Wang, Guangwen Lu, Guobo Shen, Li Yang, Jinliang Yang, Zhenling Wang, Guowen Jia, Zhaoming Su, Bin Shao, Hanpei Miao, Johnson Yiu-Nam Lau, Yuquan Wei, Kang Zhang, Lunzhi Dai, Shuaiyao Lu, Xiawei Wei