Fig. 6: IL-22 regulates BC fate in the PR8-injured lung.

A Experimental design to assess BC expansion in IL-22^Cre homozygous (IL-22 LOF) mice. Left lobes were collected for immunostaining and total RNA was isolated from the right cranial lobe for gene expression analysis. B Representative immunofluorescence localization of Pdpn (red) and Krt5 (green) in lungs of WT and IL-22 LOF mice 14 days post-PR8 infection. C Representative immunofluorescence localization of Ki67 (red) and Krt5 (green) in lung tissue of PR8-infected WT, IL-22 LOF, and IL-22ra1^fl/fl/Shh-Cre (IL-22r cLOF) mice. D Quantification of (B). The fraction of the Krt5 stained area was normalized to the area of the damaged alveolar epithelium (DAPI⁺Pdpn⁻). Data are presented as mean values ± SEM. n = 5, 3, 4, 4 for naïve, 11dpi, 14dpi, and 17dpi conditions, respectively). All analyzed samples were biologically independent. Statistical analysis was performed by Mann–Whitney two-tailed U-test (*P < 0.05). Source data are provided as a Source Data file. E qPCR detection of Krt5 mRNA in total lung RNA of PR8-infected WT and IL-22 LOF mice. Data are presented as mean values ± SEM. n = 5, 3, 5, 5, 7, 5, 5, 6 for 11dpi WT/KO, 14dpi WT/KO, 17dpi WT/KO, 21dpi WT/KO conditions, respectively. All analyzed samples were biologically independent. Statistical analysis was performed by Mann–Whitney two-tailed U-test (*P < 0.05). Source data are provided as a Source Data file. F Quantification of (C). Shown is the Ki67-labeling index for BC, expressed as a percentage of Ki67⁺, Krt5⁺ cells within areas of BC hyperplasia.). Data are presented as mean values ± SEM. n = 5 per IL-22 KO 14 dpi condition. n = 4 for all other conditions. All analyzed samples were biologically independent. Statistical analysis was performed by Mann-Whitney two-tailed U-test (*P < 0.05). Source data are provided as a Source Data file. G Representative immunofluorescence localization of Krt5 (green) and Scgb3a2 (red) in lungs of PR8-infected WT, IL-22 LOF and IL-22r cLOF mice. H Experimental design for scRNAseq of PR8-infected IL-22r cLOF mice (n = 5 biological replicates per group). I UMAP plot of Sca1⁺ airway enriched cells from IL-22r cLOF and C57/Bl6 control. Cell type annotation of clusters was performed based upon the expression of cell type-specific genes. UMAP plot were re-clustered based on genetic permutation to better represent changes in BC populations between experimental conditions. J Assessment of selected basal (Krt5, Krt14, Trp63) and serous (Bpifa1, Ltf, Msln) genes between IL-22r cLOF and WT control. Statistical analysis was performed by Wilcox Test (*P < 0.05, **P < 0.01, ***P < 0.001).