Fig. 4

TAMs mediate immune evasion through PD-1 signaling pathway. a Heatmap of enriched pathways (Top 15) from differentially expressed genes from CCR2^+/+ wild type mice, CCR2^+/− heterozygous mice, and CCR2^−/− animals. b Heatmap shows the expression of genes that associated with PD-1 signaling pathway is activated in carcinogenesis but repressed by CCR2 knockout. c Flow cytometry analysis demonstrates suppressed PD-1 expression in CD4⁺ and CD8⁺ T cells by CCR2 deletion (n = 6). d Representative IHC staining of F4/80, PD-1, CD8, cleaved CASP-3, Ki67 and TdT-mediated dUTP nick end labeling (TUNEL) in tumor microenvironment of CCR2 knockout ESCC mouse model. e Heatmap of gene expression profiles of human ESCC cases (n = 90) from TCGA database. f Pearson correlation analysis shows tight association of CCL2 with CCR2 and PD-1. g Gene set enrichment analysis (GSEA) between group high (n = 52) and low (n = 38) of CCL2 expression shows enriched pathways associated with PD-1 signaling. h Heatmap shows that expression of PD-1 signaling pathway associated genes is correlated with CCL2 expression in human ESCC