Fig. 1

Inflammatory effect of SARS-CoV-2 spike protein in human FLS. Plasmids encoding ACE2 or SARS-CoV-2 spike protein transfected into HEK 293 cells. At 48 h after transfection, cells were harvested for immunoblot to validate their expression. A Immunoblot showing expression of ACE2 and SARS-CoV-2 spike protein. GAPDH was used for loading control. Human FLS were transduced with a lentivirus vector carrying SARS-CoV-2 spike protein (Spike) or empty vector (Mock). At 48 h after lentiviral transduction, cells and supernatant were harvested for qPCR and ELISA, respectively. B qPCR analysis of IL-6, MCP-1, TNF-α, IL-1β, and IFN-γ in the Mock and Spike groups. C Protein levels of IL-6, MCP-1, and TNF-α in the supernatant of Mock and Spike groups. Data are shown as the mean ± SEM. **P < 0.005 (unpaired/two-tailed t test)