Live attenuated vaccination protects aged chimeric ACE2 mice from severe SARS-CoV-2 pathogenicity in vivo
Fig 8
Lung pathology upon infection.
(A) Lungs of young and aged chACE2 mice infected with wt virus or LAVNsp16 were resected at four days postinfection (n = 3). Upon fixation with paraformaldehyde (PFA), tissues were embedded in paraffin. To visualize lung infiltration, 5 µm tissue sections were stained with hematoxylin and eosin (H&E). Slides were scanned by S210 digital slide scanner from Hamamatsu (0.23 µm/pixel; S210, Hamamatsu, Japan). Pictures were generated using the Case Viewer software (3DHistech, Hungary). One representative slide per condition is shown. (B) H&E score of lungs of naïve, WT-, and LAVNsp16 -infected mice as shown in (A). Histopathology was assed by scoring perivascular, peribronchial, intrabronchial, or parenchymal inflammatory events (total score 0 -16). Data are presented as mean ± s.d. (n = 3). (C) As surrogate for epithelial barrier damage, protein concentration in BAL samples of aged animals sacrificed on day two and day four postinfection was determined by BCA assay. Results are shown as mean + /- s.d.