Figure 5.

Adoptive transfer of Pmel-1 T cells engineered with mIL-12 caused regression of large established B16 melanoma without the need for interleukin-2 (IL-2) administration and vaccination. (a) Pmel-1 T cells were transduced with mIL-12 viral vectors, including MSGV1.mIL12*, MSGV1.NFAT.mIL12.PA2**. Tumor-bearing C57BL/6 mice (n = 5) were adoptive transferred with 1 × 10⁶ native pmel-1 T cells only (P only) or 1 × 10⁶ native pmel-1 T cells combined with IL-2 600,000 IU daily for 3 days and rVVhgp100 vaccine (PVI). 1 × 10⁵ pmel-1 T cells engineered with mIL-12 vectors were transferred without IL-2 and vaccine. All the mice received 5 Gy lymphodepleting irradiation before infusion. Tumor sizes were assessed with serial measurements. Error bars represent SE of the mean (*^,**P < 0.01 compared with PVI). (b) Body weight of each group was measure at different days (baseline = 100%). (c) The survival of tumor-bearing mice that received cell transfer was determined as shown (*^,**P < 0.05 compared with PVI). The data represents one of two independent experiments (n = 5 animals per group).