Figure 6. The increased frequency of CD4⁺, CD8⁺ T cells and CD11c⁺ DCs at the tumor site after combination treatment.

The tumor samples on day 7 after treatment initiation were assayed (n = 3 for each group). (A) Immunohistochemical analysis showed that marked infiltration of tumor-specific CD8⁺ CTLs into tumor tissues from combination-treated mice. a: control group; b: CCL21 treated group; c: anti-CD25 treated group; d: CCL21 combined with anti-CD25 treated group. Scale bar, 100 µm. (B) Flow cytometry analysis revealed that the combination treatment enhanced the frequency of effector cells at the tumor site, significantly more tumor-infiltrating CD4⁺, CD8⁺ T cells and CD11c⁺ DCs. *P < 0.05, **P < 0.01, compared with the control group. Similar results were obtained in three independent experiments.