Fig. 1.

CD8⁺ T-cell priming in DLNs and their trafficking to tumor sites via the MIG/CXCR3 pathway. (A) MC38-bearing mice were treated with PD-L1 mAb on days 5, 10, and 15. (B and C) Tumor sizes of mice with CD8⁺ T-cell depletion (B) or DLN ablation (C) on day 4 are shown. Data represent the means ± SEM of five mice. (D) Cytokine and chemokine levels in the serum 1 d after the second therapy were detected by bead array. Data are representative of three mice (Left). MIG level in the serum was measured by ELISA. Data represent the means ± SEM of 11 mice. ***P < 0.001, two-tailed Student t test (Right). (E) CD8⁺ T cells of DLNs 1 d after the second therapy were stained with anti-CD44 mAb and anti-CXCR3 mAb. (F) The numbers of CXCR3⁺ CD44⁺ CD8⁺ T cells in distal LNs (disLNs) or DLNs of PD-L1 mAb-treated mice were calculated 1 d after the second therapy. Numbers of CXCR3⁺ CD44⁺ CD8⁺ T cells in LNs of tumor-free mice were used as a control (LN). ***P < 0.001, one-way ANOVA analysis. (G) Cells isolated from tumor mass 1 d after the second therapy were stained with anti-CD45 mAb and anti-CD8 mAb (Upper). The frequency of CD8⁺ T cells among CD45⁺ cells and number of CD8⁺ T cells per mg of tumor tissue were calculated (Lower). Data represent the means ± SEM of five mice. **P < 0.01, ***P < 0.001, one-way ANOVA analysis. (H) Tumor sizes of mice treated with anti–PD-L1 mAb along with anti-CXCR3 mAb on days 5 and 10 are shown. Data represent the means ± SEM of five mice. (I) Tumor sizes of mice treated with anti–PD-L1 mAb and FTY720. FTY720 was injected on day 4 and every 2 d for 3 wk. Data represent the means ± SEM of five mice. Data are representative of two independent experiments.