RESUMEN
There is an urgent need for antiviral agents that treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We screened a library of 1900 clinically safe drugs against OC43, a human beta coronavirus that causes the common cold, and evaluated the top hits against SARS-CoV-2. Twenty drugs significantly inhibited replication of both viruses in cultured human cells. Eight of these drugs inhibited the activity of the SARS-CoV-2 main protease, 3CLpro, with the most potent being masitinib, an orally bioavailable tyrosine kinase inhibitor. X-ray crystallography and biochemistry show that masitinib acts as a competitive inhibitor of 3CLpro. Mice infected with SARS-CoV-2 and then treated with masitinib showed >200-fold reduction in viral titers in the lungs and nose, as well as reduced lung inflammation. Masitinib was also effective in vitro against all tested variants of concern (B.1.1.7, B.1.351, and P.1).
Asunto(s)
Antivirales/farmacología , Tratamiento Farmacológico de COVID-19 , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Coronavirus Humano OC43/efectos de los fármacos , Inhibidores de Cisteína Proteinasa/farmacología , SARS-CoV-2/efectos de los fármacos , Tiazoles/farmacología , Células A549 , Animales , Antivirales/química , Antivirales/metabolismo , Antivirales/uso terapéutico , Benzamidas , COVID-19/virología , Dominio Catalítico , Proteasas 3C de Coronavirus/química , Proteasas 3C de Coronavirus/metabolismo , Coronavirus Humano OC43/fisiología , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/metabolismo , Células HEK293 , Humanos , Concentración 50 Inhibidora , Ratones , Ratones Transgénicos , Pruebas de Sensibilidad Microbiana , Piperidinas , Piridinas , SARS-CoV-2/enzimología , SARS-CoV-2/fisiología , Tiazoles/química , Tiazoles/metabolismo , Tiazoles/uso terapéutico , Carga Viral/efectos de los fármacos , Replicación Viral/efectos de los fármacosRESUMEN
There is an urgent need for anti-viral agents that treat SARS-CoV-2 infection. The shortest path to clinical use is repurposing of drugs that have an established safety profile in humans. Here, we first screened a library of 1,900 clinically safe drugs for inhibiting replication of OC43, a human beta-coronavirus that causes the common-cold and is a relative of SARS-CoV-2, and identified 108 effective drugs. We further evaluated the top 26 hits and determined their ability to inhibit SARS-CoV-2, as well as other pathogenic RNA viruses. 20 of the 26 drugs significantly inhibited SARS-CoV-2 replication in human lung cells (A549 epithelial cell line), with EC50 values ranging from 0.1 to 8 micromolar. We investigated the mechanism of action for these and found that masitinib, a drug originally developed as a tyrosine-kinase inhibitor for cancer treatment, strongly inhibited the activity of the SARS-CoV-2 main protease 3CLpro. X-ray crystallography revealed that masitinib directly binds to the active site of 3CLpro, thereby blocking its enzymatic activity. Mastinib also inhibited the related viral protease of picornaviruses and blocked picornaviruses replication. Thus, our results show that masitinib has broad anti-viral activity against two distinct beta-coronaviruses and multiple picornaviruses that cause human disease and is a strong candidate for clinical trials to treat SARS-CoV-2 infection.
