Depletion of Tregs by anti-CD25 mAbs in SLC-treated mice. (A) Representative FACs plots of CD25+ Foxp3+ Tregs gated on CD4+ T cells in tumors on day 1 to 9 post-treatment. (B) Representative staining of Foxp3+ Tregs in the tumor tissue (dark brown). (C) A curve diagram was summarized for the results from all treated and control mice. (D) The sharp increased frequency of Tregs from day 7 to day 9. Control: control group; SLC: SLC group; SLC + anti-CD25: combination therapy group. Values were presented as mean ± SD; n = 5 mice/group. * P < 0.05, ** P < 0.01 vs control or indicated comparison on day 1 to 9. Results were obtained in three independent experiments. Bar = 50 μm.