Extended Data Fig. 1: Characterization of SARS-CoV-2 virus stocks.

a. Cytopathic effect inhibition assay measuring the capacity of 40 µM of the indicated compound to inhibit SARS-CoV-2-mediated cell death. Calu-3 cells were infected with SARS-CoV-2 at an MOI of 0.05, and cell death was measured 96 hours post-infection. Significance was not calculated, as n = 2 biological replicates. b. Levels of compound-induced cytotoxicity in the absence of SARS-CoV-2. c. Viral infection of parental Vero-E6 cells or Vero-E6 cells overexpressing furin. Cells were infected with SARS-CoV-2 at an MOI of 0.05, and infectious viral particles were quantified by TCID₅₀ 24 hours post infection (hpi). Significance was determined by two-sided t-test, n = 3 biological replicates. d. Human pulmonary microvascular endothelial cells (HPMEC) overexpressing human ACE2 (HPMEC/ACE2) were infected with SARS-CoV-2 at an MOI of 0.05, and bright field microscopy images were captured at 10X magnification. Scale bar indicates 500 micrometers. Arrows indicate multinucleated syncytia. These images are representative of n = 3 biological replicates. For all panels: error bars denote mean ± s.e.m., significance is indicated as: n.s.=not significant, *= P < 0.05, **= P < 0.01, ***=P < 0.001, ****= P < 0.0001.