Journal: PeerJ
Article Title: SARS-CoV-2 Delta (B.1.617.2) variant replicates and induces syncytia formation in human induced pluripotent stem cell-derived macrophages
doi: 10.7717/peerj.14918
Figure Lengend Snippet: (A) Composite fluorescence microscopy of iMΦ infected with SARS-CoV-2 Delta and Omicron variants (MOI = 0.1). Cells were adsorbed with virus for 2 h and fixed at 72 hpi. Cells were stained with primary anti-SARS-CoV-2 N antibody followed by secondary Alexa Fluor 568-conjugated anti-mouse IgG antibody and Alexa Fluor 488-conjugated phalloidin. Cell nuclei were counterstained with DAPI. Scale bars, 50 µm. (B) Percentage of iMΦ positive for SARS-CoV-2 N after infection with SARS-CoV-2 Delta and Omicron variants. Data were shown as means ± SD ( n = 3 fields of view in each group). (C) Replication kinetics of SARS-CoV-2 Delta and Omicron variants in iMΦ. TCID 50 assay on A549-ACE2 cells was used to titrate the virus in the cell supernatants of Delta- or Omicron-infected iMΦ (MOI =0.1) at 0, 24, 48, and 72 hpi. Data were shown as means ± SD ( n = 3 in each group).
Article Snippet: Human epithelial lung carcinoma cells stably overexpressing human ACE2 (A549-ACE2; a549d-cov2r; InvivoGen, San Diego, CA, USA), human hepatocellular carcinoma cells (Huh-7; ATCC PTA-4583), and human embryonic kidney epithelial cells (293T/17; ATCC CRL-11268) stably overexpressing human ACE2 (293T/17-ACE2) were cultured in DMEM (Cat# SH30243.02; Cytiva, Marlborough, MA, USA) with 10% fetal bovine serum (FBS; Cat# F7524; Sigma, St. Louis, MO, USA).
Techniques: Fluorescence, Microscopy, Infection, Virus, Staining