Skip to main content
. 2011 Jan 17;6(1):e16241. doi: 10.1371/journal.pone.0016241

Figure 7. Combined TRAIL therapy and CTL adoptive immunotherapy effectively suppressed colon carcinoma metastasis.

Figure 7

A. IFN-γ and TNFα expression in activated CD8+ T cells. Primary CD8+ T cells were purified from spleens of naïve mice and stimulated with anti-CD3 and CD28 mAbs for 3 and 24 h, respectively. The tumor-specific CD8+ T cells were stimulated with irradiated tumor cells for 3 and 24 h, respectively. The un-stimulated and stimulated cells were then analyzed for IFN-γ and TNFα mRNA level by RT-PCR. B. Function of TRAIL in CTL-mediated tumor rejection. CT26 cells (1×105 cells/mouse) were injected into mice. Five days later, perforin-deficient CTLs (pfp CTL, 1×106 cells/mouse) were mixed with IgG or TRAIL neutralizing mAb (50 µg/mouse) and injected into the tumor-bearing mice. IgG and TRAIL neutralizing mAb (100 µg/mouse) were injected again into the tumor-bearing mice 2 days later. Mice were sacrificed 14 days after CTL treatment and analyzed for lung metastasis. Images of lungs from representative mice are shown. The number of lung tumor nodules was enumerated in a single-blinded fashion. Each dot represents total tumor counts from a single mouse. The difference between CTL+IgG control group and CTL+Anti-TRAIL mAb group is statistically significant (p = 0.03). C. Combined TRAIL and CTL adoptive immunotherapy effectively suppressed colon carcinoma metastasis. CT26 cells (1×105 cells/mouse) were injected into mice. Five days later, pfp CTLs (1×106 cells/mouse), TRAIL (200 µg/mouse), or both pfpCTL and TRAIL were injected into the tumor-bearing mice. Mice groups that received TRAIL or both pfpCTL and TRAIL were injected with TRAIL (200 µg/mouse) again every 2 days for 4 more times. Mice were sacrificed 16 days after tumor transplantation and analyzed for lung metastasis. The number of lung tumor nodules was enumerated in a single-blinded fashion. Each dot represents total counts from a single mouse. Counts greater than 250 are expressed as ≥250. The difference between control and TRAIL treatment group is not statistically significant (p = 0.15). The differences between control and pfpCTL treatment alone group and between control and pfpCTL+TRAIL treatment group are both statistically significant (p<0.001).