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. 2021 Oct 22;7(43):eabj3627. doi: 10.1126/sciadv.abj3627

Fig. 4. Differences in histopathological changes in lungs of rhesus macaques inoculated with D614G, B.1.1.7, or B.1.351.

Fig. 4.

Three groups of six adult rhesus macaques were inoculated with SARS-CoV-2 variants D614G, B.1.1.7, or B.1.351. On 6 dpi, all animals were euthanized and necropsies were performed. Lungs were assessed for the presence of interstitial pneumonia. Moderate (A) and mild (B and C) interstitial pneumonia were observed. In moderate lesions, edema (asterisk), fibrin (arrow head), and type II pneumocyte hyperplasia (arrow) were detected (D). Type II pneumocyte hyperplasia was observed in the mild lesions (E and F). By immunohistochemistry for SARS-CoV-2 N protein, moderate amounts of antigen-positive pneumocytes (arrows) were detected in D614G-inoculated animals (G), whereas scattered numbers of antigen-positive pneumocytes (arrows) were detected in B.1.1.7- and B.1.351-inoculated animals (H and I). Scale bars, 200 μM (A to C) or 20 μM (D to I). Histological lesion severity was scored per lung lobe according to a standardized scoring system evaluating the presence of interstitial pneumonia, type II pneumocyte hyperplasia, edema and fibrin, and perivascular lymphoid cuffing (score, 0 to 5); these values were combined per lung lobe and graphed (J). Presence of viral antigen was scored per lung lobe according to a standardized scoring system (0 to 5); these values were combined per lung lobe and graphed (K). Statistical analysis (J and K) was performed using a Kruskal-Wallis test with Dunn’s multiple comparisons tests, and P values <0.05 are indicated. IHC, immunohistochemistry.