Fig. 2

PM2.5 exposure promotes expansion of PD-L1^high neutrophils. (A) UMAP visualization of 12 neutrophil subpopulations (left) and 3 neutrophil subsets in the lungs. (B) Boxplot showing the counts of each neutrophil subsets across groups. (C) Representative differentially expressed genes and GO enrichment pathways for each subset. (D) Flow cytometric analysis of PD-L1^high neutrophils in the lungs: representative plots of PD-L1^high neutrophils (upper), and quantifications are depicted as MFI (lower left) and percentage (lower right). (E) Flow cytometric analysis of PD-L1^high cells in isolated neutrophils: representative plots of PD-L1^high neutrophils (left), and quantifications are depicted as MFI (middle) and percentage (right). (F) Immunofluorescence images for PD-L1 expression on isolated neutrophils (upper) and MFI for PD-L1 staining (bottom). The data are shown as means ± SEM. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001