Establishing SARS-CoV-2 Infection Models

BHK21 cells were maintained in MEM alpha medium (Cytiva; Hyclone, Marlborough, MA) containing 10% FBS (Cytiva; Hyclone, Marlborough, MA), 1× Penicillin Streptomycin (PS) solution (100 IU/mL Penicillin and 100 μg/mL Streptomycin, Corning, New York), and 1× HEPES buffer (Biological Industries, Israel). HEK293T/17 cells and Vero E6 cells were maintained in 10% FBS in DMEM/High glucose medium (Cytiva; Hyclone, Marlborough, MA) with 1× PS solution. Calu-3 cells were maintained in 10% FBS in MEM medium (ThermoFisher, Waltham, MA) with 1× PS solution. Human ACE2 (hACE2) overexpression in BHK21 cells was introduced by the lentiviral vector carrying the hACE2 gene as described previously (Su et al., 2020 (link)). SARS-CoV-2 virus (hCoV-19/Taiwan/4/2020) was kindly provided by the Taiwan Centers for Disease Control and was amplified in Vero E6 cells in M199 medium with 2 μg/mL TPCK-trypsin. All SARS-CoV-2 experiments were performed in a biosafety level 3 (BSL-3) laboratory. 2-Bromohexadecanoic acid (2BP) was purchased from Sigma-Aldrich (Darmstadt, Germany).