Maria Florencia Gomez Castro
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Researcher at Department of Molecular Microbiology, Washington University School of Medicine
Cholesterol 25-hydroxylase (CH25H) is an interferon-stimulated gene (ISG) that shows broad antiviral activities against a wide range of enveloped viruses. Here, using an ISG screen against VSV-SARS-CoV and VSV-SARS-CoV-2 chimeric viruses, we identified CH25H and its enzymatic product 25-hydroxycholesterol (25HC) as potent inhibitors of virus replication. Mechanistically, internalized 25HC accumulates in the late endosomes and blocks cholesterol export, thereby restricting SARS-CoV-2 spike protein catalyzed membrane fusion. Our results highlight a unique antiviral mechanism of 25HC and provide the molecular basis for its possible therapeutic development. ### Competing Interest Statement M.S.D. is a consultant for Inbios, Eli Lilly, Vir Biotechnology, NGM Biopharmaceuticals, and Emergent BioSolutions and on the Scientific Advisory Board of Moderna. The Diamond laboratory at Washington University School of Medicine has received sponsored research agreements from Moderna. Invention disclosure filed with Washington University in St. Louis for the recombinant VSV-SARS-CoV-2 used herein.
Pathogenic coronaviruses represent a major threat to global public health. Here, using a recombinant reporter virus-based compound screening approach, we identified several small-molecule inhibitors that potently block the replication of the newly emerged severe acute respiratory syndrome virus 2 (SARS-CoV-2). Two compounds, nitazoxanide and JIB-04 inhibited SARS-CoV-2 replication in Vero E6 cells with an EC50 of 4.90 μM and 0.69 μM, respectively, with specificity indices of greater than 150. Both inhibitors had in vitro antiviral activity in multiple cell types against some DNA and RNA viruses, including porcine transmissible gastroenteritis virus. In an in vivo porcine model of coronavirus infection, administration of JIB-04 reduced virus infection and associated tissue pathology, which resulted in improved body weight gain and survival. These results highlight the potential utility of nitazoxanide and JIB-04 as antiviral agents against SARS-CoV-2 and other viral pathogens. ### Competing Interest Statement The Boon laboratory has scientific research agreements with AI therapeutics, Greenlight Biosciences and Nano Targeting & Therapy Biopharma Inc. M.S.D. is a consultant for Inbios, Eli Lilly, Vir Biotechnology, NGM Biopharmaceuticals, and Emergent BioSolutions and on the Scientific Advisory Boards of Moderna and Immunome. The Diamond laboratory at Washington University School of Medicine has received unrelated sponsored research agreements from Moderna, Vir Biotechnology, and Emergent BioSolutions.