Fig. 6

Loss of tyrosinase in B16 melanoma unleashes T cell-mediated tumor immunity of PD-1 deficient mice. A The tumor weight of Tyr^−/− B16-F10 cell grafted Pdcd1^−/− and B6 mice. B Quantification of tumor-infiltrating T cells by flow cytometry in Tyr^−/− B16-F10 tumors from Pdcd1^−/− and B6 mice. C Representative flow cytometry analysis of CTLA-4⁺ cells in Tyr^−/− B16-F10 tumors from Pdcd1^−/− and B6 mice. Cells were identified based on CD45⁺, TCR-β⁺, CD4⁺, and CD8⁺ markers. D Quantification of the frequency of CTLA-4⁺ cells within CD4⁺ and CD8⁺ T cells in Tyr^−/− B16-F10 tumors from Pdcd1^−/− and B6 mice. E Flow cytometric analysis of Foxp3 expression in Tyr^−/− B16-F10 tumors from Pdcd1^−/− and B6 mice. Proportion of Foxp3 in CD4⁺ T cells of Tyr^−/− B16-F10 tumors from Pdcd1^−/− and B6 mice. F q-PCR analyses of Tbx21, Nr4a1, TNF-α and IFN-γ mRNAs in in Tyr^−/− B16-F10 tumors from Pdcd1^−/− and B6 mice (WT tumors, n = 4; Tyr^−/− tumors, n = 4). Each point represents the mean value obtained from two replicates for an individual mouse. Data in 6 A-E are presented as mean ± SEM (B6 mice, n = 7; Pdcd1^−/− mice, n = 7), representative of two independent experiments. Statistical significances were calculated using Student’s t -test (* p < 0.05; ** p < 0.01; *** p < 0.001; ns, not significant)