Live attenuated vaccination protects aged chimeric ACE2 mice from severe SARS-CoV-2 pathogenicity in vivo
Fig 7
Strong immune cell infiltration, enhanced ISG expression, and enhanced tissue damage in the lung of aged chACE2 mice.
Immune responses were analyzed in 46 to 55 weeks old chACE2 mice at the indicated time points postinfection with 7x104 PFU of wt virus or LAVNsp16 (as shown in Fig 6). (A-E) Lung infiltration by CD45+CD11b+ monocytes, CD45+Gr-1high neutrophils, CD45+CD49b+ natural killer cells, CD45+CD11b+CD11c+ macrophages, and CD45+CD8+ T cells was determined by antibody staining of cells in BAL followed by flow cytometry. The mean cell number + /- s.d. as well as individual data points are shown. Statistical analysis was done using unpaired two-tailed t-tests (F) mRNA levels of Ifi44, Oas1 and Ifnb1 present in lung tissue of infected animals were determined by RT-qPCR and normalized to GAPDH (ΔΔCt). For statistical analysis, unpaired two-tailed t-tests were performed.