Characterization of Human Cell Lines

Human lung epithelial cell lines A549 (ATCC CCL-185) and Calu-3 (ATCC HTB-55); HEK 293T cells, a human kidney epithelial cell line (HEK 293T/17, ATCC CRL-11268); and Vero E6 cells (Vero 76, clone E6, Vero E6, ATCC CRL-1586), an African Green Monkey kidney epithelial cell line, were authenticated by ATCC (American Type Culture Collection). A monoclonal ACE2-expressing A549 cell line (A549-ACE2) was a kind gift from Brad Rosenberg. Monoclonal ACE2-expressing STAT1-knockout A549 cells (A549-ACE2ΔSTAT1) were generated as previously described (44 (link), 45 (link)). All cell lines were cultured under humidified 5% CO₂ conditions in 10% vol/vol fetal bovine serum (FBS, Thermo Fisher Scientific) and 100 I.U. penicillin and 100 µg/mL streptomycin (Pen/Strept, Corning) in Dulbecco’s Modified Eagle Medium (DMEM, Corning). Cells were confirmed negative for mycobacteria monthly (Lonza).