Depletion of CD4+CD25+ regulatory T cells can promote local immunity to suppress tumor growth in benzo[a]pyrene-induced forestomach carcinoma

Figure 5 Apoptotic cells in forestomach tumors. Apoptotic cells were detected by TUNEL-staining as described in Materials and Methods. Apoptotic cells were revealed by a brown color. Stomach tumor nodules of mice were surgically obtained at wk 16 (A-C) and wk 32 (D-F) after the first administration of BaP. Significant apoptotic cells were found at wk 32 in BaP + PC61-treated mice. A and D: Control mice; B and E: BaP+IgG-treated mice; C and F: BaP + PC61-treated mice.