Characterization of a pangolin SARS-CoV-2-related virus isolate that uses the human ACE2 receptor

Various SARS-CoV-2-related coronaviruses have been increasingly identified in pangolins,showing a potential threat to humans.Here we report the infectivity and pathogenicity of the SARS-CoV-2-related virus,PCoV-GX/P2V,which was isolated from a Malayan pangolin(Manis javanica).PCoV-GX/P2V could grow in human hepatoma,colorectal adenocarcinoma cells,and human primary nasal epithelial cells.It replicated more efficiently in cells expressing human angiotensin-converting enzyme 2(hACE2)as SARS-CoV-2 did.After intranasal inoculation to the hACE2-transgenic mice,PCoV-GX/P2V not only replicated in nasal turbinate and lungs,but also caused interstitial pneumonia,characterized by infiltration of mixed inflammatory cells and multifocal alveolar hemorrhage.Existing population immunity established by SARS-CoV-2 infection and vaccination may not protect people from PCoV-GX/P2V infection.These findings further verify the hACE2 utility of PCoV-GX/P2V by in vivo experiments using authentic viruses and highlight the importance for intensive surveillance to prevent possible cross-species transmission.

Cross-species recognition of bat coronavirus RsYN04 and cross-reaction of SARS-CoV-2 antibodies against the virus

Following the outbreak of coronavirus disease 2019(COVID-19),several severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)-related coronaviruses have been discovered.Previous research has identified a novel lineage of SARS-CoV-2-related CoVs in bats,including RsYN04,which recognizes human angiotensin-converting enzyme 2(ACE2)and thus poses a potential threat to humans.Here,we screened the binding of the RsYN04receptor-binding domain(RBD)to ACE2 orthologs from 52animal species and found that the virus showed a narrower ACE2-binding spectrum than SARS-CoV-2.However,the presence of the T484W mutation in the RsYN04 RBD broadened its range.We also evaluated 44 SARS-CoV-2antibodies targeting seven epitope communities in the SARS-CoV-2 RBD,together with serum obtained from COVID-19 convalescents and vaccinees,to determine their cross-reaction against RsYN04.Results showed that no antibodies,except for the RBD-6 and RBD-7 classes,bound to the RsYN04 RBD,indicating substantial immune differences from SARS-CoV-2.Furthermore,the structure of the RsYN04 RBD in complex with cross-reactive antibody S43 in RBD-7 revealed a potently broad epitope for the development of therapeutics and vaccines.Our findings suggest RsYN04 and other viruses belonging to the same clade have the potential to infect several species,including humans,highlighting the necessity for viral surveillance and development of broad anticoronavirus countermeasures.