Protection against SARS-CoV-2 infection is achieved when simvastatin is supplied before infection and causes membrane reorganisation

BACKGROUND: The COVID-19 pandemic demonstrated the need for a larger pallet of antivirals. Ideally cheap, safe, widely available, easy to administer and resistant to virus mutation. Statins meet these criteria and repurposing statins, which inhibit cholesterol synthesis, is appealing since enveloped viruses need to cross the cholesterol-rich plasma membrane both upon cell infection and egress of new virus particles. OBJECTIVES: To investigate whether, when and how simvastatin has antiviral effects against SARS-CoV-2 infection and how simvastatin treatment affects the organisation of the plasma membrane. METHODS: Calu-3 and Vero cells were infected with the D614G and BA.1 SARS-CoV-2 virus strains. Infection, binding and internalisation was assessed using RT-qPCR. Membrane order was assessed by live cell fluorescence microscopy and ACE2 distribution by immunofluorescence. RESULTS: Simvastatin reduces SARS-CoV-2 infection in Calu-3 and Vero cells in a dose-dependent manner at clinically relevant concentrations in a virus strain independent manner. Importantly, simvastatin pre-treatment was necessary for the antiviral effect. Simvastatin treatment reduced the membrane order, i.e. the lipid packing, of the plasma membrane and resulted in a higher intracellular presence of ACE2. The membrane organisation changes neither affected virus binding at 4 °C nor internalisation of the pre-bound virus particles. CONCLUSIONS: Pre-treatment is essential for the antiviral effect of simvastatin and is accompanied by a rearrangement of the plasma membrane with reduced lipid packing and altered ACE2 distribution. Our results suggest that simvastatin could be effective when taken prophylactically and may be effective when used early in the course of COVID-19 disease.