Potential host range of multiple SARS-like coronaviruses and an improved ACE2-Fc variant that is potent against both SARS-CoV-2 and SARS-CoV-1

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a currently uncontrolled pandemic and the etiological agent of coronavirus disease 2019 (COVID-19). It is important to study the host range of SARS-CoV-2 because some domestic species might harbor the virus and transmit it back to humans. In addition, insight into the ability of SARS-CoV-2 and SARS-like viruses to utilize animal orthologs of the SARS-CoV-2 receptor ACE2 might provide structural insight into improving ACE2-based viral entry inhibitors. Here we show that ACE2 orthologs of a wide range of domestic and wild animals support entry of SARS-CoV-2, as well as that of SARS-CoV-1, bat coronavirus RaTG13, and a coronavirus isolated from pangolins. Some of these species, including camels, cattle, horses, goats, sheep, pigs, cats, and rabbits may serve as potential intermediate hosts for new human transmission, and rabbits in particular may serve as a useful experimental model of COVID-19. We show that SARS-CoV-2 and SARS-CoV-1 entry could be potently blocked by recombinant IgG Fc-fusion proteins of viral spike protein receptor-binding domains (RBD-Fc) and soluble ACE2 (ACE2-Fc). Moreover, an ACE2-Fc variant, which carries a D30E mutation and has ACE2 truncated at its residue 740 but not 615, outperforms all the other ACE2-Fc variants on blocking entry of both viruses. Our data suggest that RBD-Fc and ACE2-Fc could be used to treat and prevent infection of SARS-CoV-2 and any new viral variants that emerge over the course of the pandemic.