Development of a new platform for testing antiviral drugs using coronavirus-infected human nasal mucosa organoids

Abstract

To establish a coronavirus (CoV) infection model using human nasal mucosa organoids for testing antiviral drugs and evaluate the feasibility of using human nasal mucosa organoids with viral infection as platforms for viral research and antiviral drug development. Human nasal mucosa organoids were tested for susceptibility to SARS-CoV-2 and HCoV-OC43 pseudoviruses. In a P3 laboratory, nasal mucosa organoids were infected with the original strain of SARS-CoV-2 and 4 variant strains, and the infection conditions were optimized. The viral loads in the culture supernatants were measured at different time points using RT-qPCR, and immunofluorescence assay was employed to localize SARS-CoV-2 nucleocapsid protein to determine the type of the infected cells. In the optimized nasal mucosa viral infection model, the antiviral effects of camostat and bergamot extract (which were known to inhibit SARS-CoV-2) were tested and the underlying molecular mechanisms were explored. In the optimized nasal mucosa organoid models infected with SARS-CoV-2 and HCoV-OC43 pseudoviruses, the viral load in the culture supernatants increased significantly during the period of 2 to 24 h following the infection, which confirmed infection of the organoids by both of the pseudoviruses. The nasal mucosa organoids could be stably infected by the original SARS-CoV-2 strain and its 4 variant strains, validating successful establishment of the viral infection model, in which both camostat and bergamot extract exhibited dose-dependent antiviral effects. Human nasal mucosa organoids with SARS-CoV-2 infection can serve as platforms for screening and testing antiviral drugs, particularly those intended for nasal administration.