Fig. 5

PPARα depletion attenuates tumor killing and the antigen-presenting ability of ACE-overexpressing macrophages. A In vitro tumor-killing assay. B16-F10 cells and TPMs prepared from WT, A10-PPARα or A10-PPARα-Cre naïve mice were mixed at a 1:1 ratio and incubated at 37 °C for 24 h. LDH levels in the cultures were measured via absorbance, and the values were used to calculate the tumor-killing rates. B In vitro antigen restimulation assay. Inguinal lymph node (iLN) cells were isolated from tumor-bearing mice 11 days after tumor inoculation and were restimulated with TRP-2 peptide (100 μg/mL) at 37 °C for 72 h. IFN-γ concentrations in the culture medium were measured via ELISA. C In vitro antigen presentation assay. CD8⁺ T cells were isolated from the iLNs of tumor-bearing WT mice 11 days after tumor inoculation. TPMs were also prepared from naive WT, A10^-PPARα, or A10-PPARα-Cre mice and cocultured with CD8⁺ T cells in the presence of the TRP-2 peptide (100 μg/mL) at 37 °C for 24 h. The expression (MFI) of CD69 and the percentages of IFN-γ-producing cells in the CD8⁺ T-cell population were measured via flow cytometry. The cumulative data are shown as the mean ± SEM of six samples from two independent experiments. All MFI values are represented as fold changes (the average value of WT was used as 1). One-way ANOVA was used to analyze the data for significant differences. *p < 0.05 and **p < 0.01; ns not significant