Cisplatin pretreatment enhances anti-tumor activity of cytokine-induced killer cells

Figure 4 Intratumoral infiltration of lymphocytes after combined therapy. BALB/c WT mice were injected s.c. with 1 × 10⁶ CT-26 cells and the treatment protocols were initiated 7 d later. On Day 19, consecutive tumor sections were prepared and analyzed by CD3 (A) and FoxP3 (C) staining. Ten individual fields (0.16 mm²) surrounding the apoptotic area (× 400 magnification) were chosen to count the number of intratumoral CD3⁺ T lymphocytes (B), and to determine the absolute number (D), and percentage (E) of FoxP3 + Treg cells. Experimental groups consisted of five mice per group. Representative sections from all groups are shown. Scale bar: 25 μm. Lines: median; Boxes:75% percentile; Bars (B, D) : SD. Columns : Mean Treg percentage; Bars (E): SE. ^aP < 0.05. NS: Normal saline; CIK: Cytokine-induced killer cells; DDP: Cisplatin.