Figure 1.

Cytokine mRNA and protein expression profile following infection of K18-ACE2 mice with Wuhan strain. Infected or mock mouse lung tissues were collected three days post-infection (n = 4/group). (A) The SARS-CoV-2 E gene copy number was evaluated by ddPCR using lung RNA and expressed as number per copy of Rpp30 mRNA (mean ± SD). (B) Infectious viral titers were determined in lung homogenates and expressed in TCID_50/mL (mean ± SD). (C) Gene expression was evaluated by RT-qPCR and cytokine concentration in lung homogenates determined using a 13-plex Luminex panel. Cytokine gene expression and concentration levels are presented as heatmaps with results expressed as fold (log₂) relative to mock-infected mice (mean). Statistical analyses were performed by comparing 2^(−ΔCt) values for each gene in the control group and infected groups with a nonparametric T-test. (D) Cytokine concentrations in lung homogenates. Results are expressed as mean ± SD. For protein quantification, statistical analyses were performed by comparing the normalized concentration for each cytokine in the control group and infected groups with a nonparametric t-test. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.