Journal: EBioMedicine
Article Title: Q493K and Q498H substitutions in Spike promote adaptation of SARS-CoV-2 in mice
doi: 10.1016/j.ebiom.2021.103381
Figure Lengend Snippet: Characterization of mouse-adapted SARS-CoV-2 WBP-1 in mice. (a, b) Groups of mice ( n = 5) were intranasally infected with 10-fold serial dilutions of WBP-1 virus. The infected mice were observed for weight loss and survival for 10 dpi. (c- f) Mice ( n = 6) were intranasally infected with 2 LD 50 of the WBP-1 virus and mice in the control group were mock-infected with DMEM. (c) Viral RNA copies were determined through qRT-PCR at 3 and 5 dpi in the heart, liver, lung, kidney, brain, intestine, trachea, turbinate, and spleen of WBP-1. (d) Viral titers in the lung were determined through plaque assays. (e) Cytokine (IL1β, TNFα, MCP1, and IL10) mRNA levels in the lung were evaluated at 3 and 5 dpi. Statistical significance was analyzed by unpaired Student's t tests. * p < 0.05; ** p < 0.01; *** p < 0.001 **** p < 0.0001. (f) Hematoxylin and eosin (H&E) staining of lung sections from mice infected Mouse-adapted WBP-1 virus (Exfoliated necrotic cells, black arrow; Mononuclear lymphocytes, green arrow; Inflammatory exudate, red arrow; Vascular thrombosis, blue arrow). Scale bars (black), 100 μm. Scale bars (green), 50 μm. (g) Immunohistochemical detection of viral antigen using anti-Spike protein Rabbit monoclonal antibody in bronchi and alveoli. Scale bars (black), 100 μm. Scale bars (green), 50 μm.
Article Snippet: For immunohistochemistry, fixed tissues were paraffin-embedded, sectioned, and stained with rabbit-anti ACE2 (Abcam, ab108252, 1:200), SARS-CoV-2 nucleocapsid antibody (Sino Biological, China, 40588-R001, 1:200).
Techniques: Infection, Quantitative RT-PCR, Staining, Immunohistochemical staining