Since its emergence, SARS-CoV-2 has been continuously evolving, hampering the effectiveness of current vaccines against COVID-19. mAbs can be used to treat patients at risk of severe COVID-19. Thus, the development of broadly protective mAbs and an understanding of the underlying protective mechanisms are of great importance. Here, we isolated mAbs from donors with breakthrough infection with Omicron subvariants using a single–B cell screening platform. We identified a mAb, O5C2, which possesses broad-spectrum neutralization and antibody-dependent cell-mediated cytotoxic activities against SARS-CoV-2 variants, including EG.5.1. Single-particle analysis by cryo-electron microscopy revealed that O5C2 targeted an unusually large epitope within the receptor-binding domain of spike protein that overlapped with the angiotensin-converting enzyme 2 binding interface. Furthermore, O5C2 effectively protected against BA.5 Omicron infection in vivo by mediating changes in transcriptomes enriched in genes involved in apoptosis and interferon responses. Our findings provide insights into the development of pan-protective mAbs against SARS-CoV-2.
Yi-Hsuan Chang, Min-Feng Hsu, Wei-Nan Chen, Min-Hao Wu, Wye-Lup Kong, Mei-Yeh Jade Lu, Chih-Heng Huang, Fang-Ju Chang, Lan-Yi Chang, Ho-Yang Tsai, Chao-Ping Tung, Jou-Hui Yu, Yali Kuo, Yu-Chi Chou, Li-Yang Bai, Yuan-Chih Chang, An-Yu Chen, Cheng-Cheung Chen, Yi-Hua Chen, Chun-Che Liao, Chih-Shin Chang, Jian-Jong Liang, Yi-Ling Lin, Takashi Angata, Shang-Te Danny Hsu, Kuo-I Lin
O5C2 mAb broadly recognizes the RBD of S proteins of a range of SARS-CoV-2 strains from WT to Omicron variants and blocks S protein binding to hACE2.