Targeted Drug Repurposing Against the SARS-CoV-2 E Channel Identifies Blockers With in vitro Antiviral Activity

It is difficult to overstate the impact that COVID-19 had on humankind. The pandemics etiological agent, SARS-CoV-2, is a member of the Coronaviridae, and as such, is an enveloped virus with ion channels in its membrane. Therefore, in an attempt to provide an option to curb the viral spread, we searched for blockers of its E protein viro-porin. Using three bacteria-based assays, we identified eight compounds that exhibited activity after screening a library of ca. 3000 approved-for-human-use drugs. Reassuringly, analysis of viral replication in tissue culture indicated that most of the compounds could reduce infectivity to varying extents. In conclusion, targeting a particular channel in the virus for drug repurposing may increase our arsenal of treatment options to combat COVID-19 virulence. Significance StatementThe goal of our study was to expand the treatment arsenal against COVID-19. To that end, we have decided to focus on drug therapy, and as a target - the E protein, an ion channel in the virus. Ion channels as a family are excellent drug targets, but viral channels have been underexploited for pharmaceutical point intervention. To hasten future regulatory requirements and focus the chemical search space, we screened a library of ca. 3000 approved-for-human-use drugs using three independent bacteria-based assays. Our results yielded eight compounds, which were subsequently tested for antiviral activity in tissue culture. Gratifyingly, most compounds were able to reduce viral replication, and as such, both validate our approach and potentially augment our anti-COVID tool kit.