Figure 8. PD-1 ablation induces enhanced mitochondrial metabolism of myeloid cells in tumor-bearing mice and improved T cell function.

(A-C) Expression of PPARγ in myeloid cells at the B16-F10 site in PD-1^f/f, PD-1^f/fLysMcre and PD-1^−/− mice was examined by flow cytometry. Mean percentages ± SEM (A), representative histograms (B) and contour plots (C) of PPARγ-expressing CD11b⁺Ly6C⁺, CD11b⁺F4/80⁺ and CD11c⁺MHCII⁺ subsets. (D-G) Mitochondrial metabolic activity of myeloid cells at the B16-F10 tumor site in PD-1^f/f, PD-1^f/fLysMcre and PD-1^−/− mice was examined by assessing mitochondrial membrane potential using MitoRed. MFI ± SEM of MitoRed positive CD11b⁺Ly6C⁺, CD11b⁺F4/80⁺, and CD11c⁺MHCII⁺ subsets within the CD45⁺CD11b⁺ gate (D-F) and representative plots of FACS analysis (G) are shown. (H-L) In parallel, expression of IFN-γ, IL-17A, IL-2, IL-10, RORC and ICOS in CD8⁺ T_CM and T_EM isolated from B16-F10-bearing PD-1^f/f and PD-1^f/fLysMcre mice was assessed by flow cytometry. Representative histograms (H), contour plots (I, K), and mean percentages ± SEM (J, L, M) within the CD44^hiCD62L^hi gate (for T_CM) and CD44^hiCD62^lo gate (for T_EM) cells are shown. Data are from one representative of four independent experiments. (* p< 0.05, ** p< 0.01, *** p< 0.001).