SARS-CoV-2 N protein induces a weaker inflammatory response than SARS-CoV N protein during viral infection. (A) Schematic representation of N variant function assessment. Caco-2 cells stably expressing N variants via lentiviral transduction were infected with RDPs, followed by analysis of GFP expression through flow cytometry or microscopy, and viral RNA analyzed by RT-qPCR. (B–F) Caco-2 cells stably expressing N variants were infected with RDPs for 12, 24, or 48 h, and the GFP expression was analyzed by microscopy (B) or flow cytometry (D). Scale bars, 100 μm. Total RNA extracted from the cells was evaluated by RT-qPCR (C, E, and F). Graphs show mean ± SEM (n = 3 in C, E, and F) from one representative experiment. **P < 0.01, ***P < 0.001, ****P < 0.0001, ns, not significant (unpaired, two-tailed Student’s t test). Data are representative of three independent experiments.