ACT with mTERT_198-205 CTLs is effective in several transplantable tumor models. (A) Evaluation of CTL ability to traffic to tumors. B16 melanoma cells were injected in C57BL/6-CD45.1⁺ mice. When the tumor area was ∼ 10 mm², mice received hgp-100_25-33-, mTERT_198-205-, or β-gal_96-103–specific CTLs. At 4 days after transfer, tumors were harvested for TIL analysis. Transferred CTLs were tracked as CD8⁺/CD45.2⁺ cells (left). CD8⁺/CD45.2⁺ cells were then evaluated for the staining with specific mAbs for TCR Vβ chain: anti-Vβ8.1 for β-gal_96-103, anti-Vβ11 for mTERT_198-205, and anti-Vβ13 for hgp-100_25-33 CTLs (middle). The activation status of TILs was evaluated by ICS for IFN-γ after ex vivo stimulation (right). Data are mean ± SD of 3 independent experiments. (B) Therapeutic effectiveness of ACT with the use of mTERT_198-205-specific CTLs in a melanoma model. C57BL/6 mice (top) and Rag-2^−/−γ_c^−/−mice (bottom) were implanted with B16 cells. Survival and tumor area are plotted from 3 cumulative experiments (n = 15). Mantel–Haenszel statistic analysis for survival: for C57BL/6 model, hgp-100 vs β-gal, P = .001; mTERT vs β-gal, P = .001; mTERT vs hgp-100, P = .16; for Rag-2^−/−γ_c^−/− mice, hgp-100 vs β-gal, P = .001; mTERT vs β-gal, P = .001; mTERT vs hgp-100, P = .29. (C) Therapeutic effectiveness of ACT by use of mTERT_198-205-specific CTLs in 4 tumor models. C57BL/6 mice were implanted with TRAMP-C2, MCA203, MC38, or TC-1 cells and treated as described in the melanoma model. TILs were evaluated by ICS for IFN-γ after ex vivo stimulation (right). Survival from 3 cumulative experiments (n = 15) is shown (left). Mantel-Haenszel statistics for mTERT vs β-gal comparison: C2-TRAMP, P = .027; MCA203, P = .001; MC38, P = .016; TC-1, P = .001. Transferred TILs were tracked, and IFN-γ and CD8 staining is shown on cells gated for CD45.2⁺ T cells (right). Data are mean ± SD of 3 independent experiments.