Fig. 4

PPARα depletion impairs the antitumor activity of A10-PPARα-Cre mice. A Experimental design of the murine B16-F10 tumor model. The mice received a subcutaneous (s.c.) injection of B16-F10 cells (100 μL of 1.0 × 10⁷/mL in PBS). The tumor volumes were measured, and the immunological activities of intratumor (IT) macrophages and CD8⁺ T cells were analyzed via flow cytometry on day 14 posttumor inoculation. B Representative pictures of tumors. C Tumor volumes. D Number of tumor-infiltrating macrophages. E Functional marker expression of IT macrophages. M1 markers (TNF-α, IL-6, IL-12/IL-23p40, and iNOS) and M2 markers (arginase 1 (Arg 1), IL-10, and CD206) were measured via flow cytometry, and MFI values were used to generate a heatmap. F, G Representative histograms (H) and MFI values (fold change) (I) of CD80, H-2K^b, and I-A^b expression in IT macrophages. H, I Representative histograms (F) and MFI values (fold change) (G) of PD-L1 and PD-L2 expression by IT macrophages. J–O Functional characterization of IT CD8⁺ T cells. J Representative plots of TRP-2/tetramer (Tet)⁺CD8⁺ T cells and IFN-γ⁺, TNF-α⁺, or GzmB⁺ populations among TRP-2/Tet⁺CD8⁺ T cells. K, L Percentages (K) and cell numbers (per 100 mm³ of tumor) (L) of TRP-2/Tet⁺CD8⁺ T cells. M–O Percentages of TNF-α⁺ (M), IFN-γ⁺ (N), or GzmB⁺ (O) TRP-2/Tet⁺CD8⁺ T cells. The cumulative data are shown as the means ± SEMs of six to ten samples from two or three independent experiments. All MFI values are represented as fold changes (the average value of WT was used for base = 1). One-way ANOVA was used to analyze the data for significant differences. *p < 0.05, **p < 0.01, and ***p < 0.001; ns not significant