Fig. 4: Fate mapping of human airway basal progenitor cells in vivo.

a Single-cell RNA-sequencing cellular cluster map of GFP⁺ human cell from 8 (left) and 35 (right) dpt mouse lungs. The pie plots showed the percentages of distinct cell clusters. b Feature plots showing the expression of multiple marker genes in distinct single-cell clusters of engrafted human cells. c Feature plots showing the expression of genes signatures in distinct single-cell clusters of engrafted human cells. d Immunofluorescence images of engrafted human cells with anti-GFP (green), ciliated cell marker anti-acetylated-tubulin (red), Club cell marker anti-CC10 (red) or tight junction marker anti-CLDN4 (red) antibodies staining. Scale bar, 50 μm. e Gene Ontology enrichment analysis of the differentially expressed genes identified in CLDN4⁺ CLDN3⁺ saccular cells. f Pseudo-time trajectory projected onto a UMAP of transplanted human cells using the quiescent KRT5⁺ P63⁺ airway basal progenitors as a starting point. Pseudo-time values are color-coded. g Density of each human cell population ordered by pseudo-time as computed by reversed graph embedding approach of Monocle3. h Schematic diagram showing the putative differentiation paths starting from KRT5⁺ P63⁺ airway basal progenitor cells predicted by the pseudo-time analysis. i Schematic diagram showing the putative re-epithelialization process in the fibrotic lung after human airway basal progenitor transplantation.