Fig. 3

Enhanced PD-1 and Foxp3 expression in tyrosinase-deficient tumors T Cells. A-B Flow cytometric analysis of PD-1 expression in WT and Tyr^−/− tumors. Cells were firstly gated on CD45⁺ and Lin⁻ (CD19, CD11b, NK1.1, Ly6G), then further gated on CD5⁺ TCR-β⁺, CD4⁺, and CD8⁺ cells. C Percentage of PD-1⁺ cells within CD4⁺ and CD8⁺ T cells in WT and Tyr^−/− B16-F10 tumors. D-E Flow cytometric analysis of PD-1 expression in WT and Tyr^−/− tumors. Proportion of CTLA-4⁺ cells within CD4⁺ and CD8⁺ T cells in WT and Tyr^−/− B16-F10 tumors (E). F Flow cytometric analysis of Foxp3 expression in WT and Tyr^−/− tumors. Histograms on the right show the proportion of Foxp3 in CD4⁺ T cells in WT and Tyr^−/− tumors. Data are presented as mean ± SEM (WT tumors, n = 6; Tyr^−/− tumors, n = 5). All data are representative of two independent experiments. Statistical significances were calculated using Student’s t-test (* p < 0.05; ** p < 0.01; *** p < 0.001)