Hydroxypropyl-β-Cyclodextrin depletes membrane cholesterol and inhibits SARS-COV-2 entry into HEK293T-ACEhi cells

Abstract Vaccination has drastically decreased mortality due to COVID-19 but not the rate of SARS-CoV-2 infection. Alternative strategies like inhibition of virus entry by interference with ACE2 receptors, could be warranted. Cyclodextrins (CDs) are cyclic oligosaccharides able to deplete cholesterol from membrane lipid raft, thus inducing ACE2 receptors to relocate to areas devoid of lipid rafts. To explore the possibility of reducing SARS-CoV-2 entry, we tested hydroxypropyl-β-cyclodextrin (HPβCD) in a HEK293T-ACE2hi cell line stably overexpressing human ACE2 and pseudotyped SARS-CoV-2 particles. We showed that HPβCD is not toxic to the cells for concentrations up to 5 mM and that this concentration has no significant effect on cell cycle parameters in any experimental condition tested. Exposure of HEK293T-ACEhi cells to concentrations of HPβCD starting from 2.5 mM to 10 mM showed a concentration-dependent reduction down to about 50% of the initial membrane cholesterol content. In addition, incubation of HEK293T-ACEhi cells with HIV-S-CoV2 pseudotyped particles in presence of increasing concentrations of HPβCD (from 0.1 to 10 mM) displayed a concentration-dependent effect on SARS-CoV-2 entry efficiency, with concentrations at least one order of magnitude lower than the lowest concentration showing toxic effects. These data indicate HPβCD as a strong candidate as a SARS-CoV-2 prophylactic agent.