Fbs hi

Human lung carcinoma cells, A549, overexpressing human ACE2 and human TMPRSS2 receptors were purchased from Invivogen (Cat no.: a549-hace2tpsa). A549^{+hACE2+hTMPRSS2}_mCherry cells were cultured in Dulbecco's modified Eagle's medium (DMEM, Thermo Fisher Scientific) supplemented with 10% v/v heat-inactivated fetal bovine serum (FBS HI, Biowest), 300 μg/mL hygromycin (Invivogen), 0.5 μg/mL puromycin (Invivogen) and 10 μg/mL blasticidin (Invivogen) at 37 °C and 5% CO₂. Antiviral assays with A549^{+hACE2+hTMPRSS2}_mCherry cells were performed in Mucilair medium (Epithelix).

AGS cells (ATCC CRL-1739) were cultured in Dulbecco’s Modified Eagle Medium (DMEM; Gibco) supplemented with 10% (v/v) FBS-HI (Gibco) and 1% (v/v) Antibiotic-Antimycotic (ABAM; Gibco) at 37°C in a humidified 5% CO₂ incubator. NCI-N87 cells (ATCC CRL-5822) were cultured in RPMI 1640 (Gibco) supplemented with 10% (v/v) FBS-HI and 1% (v/v) ABAM. MKN28 cells stably transfected with an empty pRc/CMV expression plasmid as described previously [64 (link)] were a gift from Dr. Osamu Nagano (Division of Gene Regulation, Institute of Advanced Medical Research, Keio University School of Medicine). MKN28 cells were grown in RPMI 1640 medium supplemented with 10% (v/v) FBS-HI (Biowest) and 1% (v/v) ABAM.