Fig. 5: IFNγ induces expression of anti-viral markers in pneumocytes and CD24+ epithelial cells.

A B6 mice were inoculated with BCG or PBS iv 40–45 days prior to intranasal challenge with SARS-CoV-2 (SCV2) B.1.351. Infected animals received an IFNγ neutralizing antibody or isotype control 1 day prior to and 1 day following SARS-CoV-2 instillation. Lungs were harvested 3 days after viral challenge and the indicated epithelial cell types were assessed for CD274 (n = 10/PBS group, n = 9/BCG group; pooled from 2 independent experiments; One-Way ANOVA with Tukey post-test) and BST2 (PBS n = 15, BCG n = 12, PBS + SCV2+iso n = 15, BCG + SCV2+iso n = 14, PBS + SCV2 + αIFNγ n = 14, BCG + SCV2 + αIFNγ n = 14; pooled from three independent experiments; one-way ANOVA with Tukey post-test) expression by flow cytometry. Not significant (ns) p > 0.05. B, C B6 mice were inoculated with BCG or PBS iv 40–45 days prior to receiving an IFNγ-neutralizing antibody or isotype control. Lungs were harvested 1 day after anti-IFNγ treatment. B Schematic of experimental outline. C Expression of CD274, BST2, and Ly6A/E across different epithelial cell types (n = 7/BCG group; pooled from two independent experiments; two-tailed unpaired t-test between BCG isotype and BCG αIFNγ for each cell-type). Not significant (ns) p > 0.05. Data are displayed as median, quartiles ± range. D, E B6 or Ifngr1^−/− mice were treated with PBS or rIFNγ intranasally on 2 consecutive days. Lungs were harvested 1 day after the last treatment. D Schematic of the experimental protocol. E Expression of CD274, BST2, and Ly6A/E across different epithelial cell types (B6 n = 10/group; two independent experiments; two-tailed unpaired t-test between PBS and rIFNγ treated B6 mice for each cell type). Not significant (ns) p > 0.05. Data are displayed as median, quartiles ± range. Source data are provided as a Source Data file.