Fig. 7: Immunolabeling of proliferation and senescence markers in SARS-CoV-2-infected hamsters.

a–c Quantification of Ki67 (a), p53 (b), and p21 (c) immunolabelled cells within alveolar epithelial proliferation foci (ep. prol.). On the right, representative pictures of immunolabeling (brown signal, arrows) in alveolar proliferation foci of SARS-CoV-2-infected hamsters at 6 and 112 days post infection (dpi). d Representative images of double immunofluorescence of Ki67 in combination with CK8⁺ ADI cells, CK14⁺ airway progenitor cells, or SCGB1A1⁺ club cells in alveolar proliferation foci at different time-points. In the top panel, cells are labeled with CK8 (green) and Ki67 (red). There are moderate numbers of double-labeled cells (arrows) at 6 dpi, whereas they are rare at 28 dpi. In the central panel, airway progenitor cells are labeled with CK14 (green) and Ki67 (red). There are moderate numbers of double-labeled cells (arrows) at both 6 and 112 dpi. In the bottom panel, cells are labeled with SCGB1A1 (green) and Ki67 (red). All stains were performed in four animals/time-point with same results. There are moderate numbers of double-labeled cells (arrows) at both 14 and 112 dpi. a–c quantification data is shown as box and whisker plots. The bounds of the box plot indicate the 25th and 75th percentiles, the bar indicates medians, and the whiskers indicate minima and maxima. Dots indicate individual values. Statistical analysis was performed by a two-tailed Mann–Whitney U test. P- and q values ≤ 0.05 were considered significant. N = 8 animals/group for mock and SARS-CoV-2 respectively. Source data is provided as a Source Data file.