Figure 2.

The Role for IFN and STAT1 Signaling in SARS-CoV-2 Infection

(A) 5 days after transduction with 2.5 × 10⁸ FFU of Ad5-hACE2, C57BL/6 mice were intranasally infected with 1 × 10⁵ PFU of SARS-CoV-2. Weight changes were monitored daily (n = 5 mice per group), and virus titers in the lungs were measured at the indicated time points using FFA (n = 3–4 mice per group per time point). Titers are expressed as FFU/g tissue.

(B) Sections of paraffin embedded lungs from SARS-CoV-2-infected Ad5-hACE2-transduced, wild-type and genetically modified C57BL/6 mice at 4 d.p.i. were stained with hematoxylin/eosin. Scale bar, 100 μm.

(C) Photographs of gross pathological lung specimens isolated from infected C57BL/6 mice at 4 d.p.i. Arrowheads indicate regions with vascular congestion and hemorrhage.

(D) Ad5-hACE2-transduced C57BL/6 mice were treated with 80 μg of poly I:C in 50 μL of PBS 6 h before intranasal infection with SARS-CoV-2. Weight changes were monitored daily, and viral titers in lungs were measured at the indicated time points.

^∗p values ≤ 0.05; ^∗∗p values ≤ 0.005; ^∗∗∗p values ≤ 0.0005; ^∗∗∗∗p values ≤ 0.0001.