TCR-IV T cells remain functional in mice with tumor escape. (A) Mean radiance of the signal emitted at the tumor site by localized T cells over time. T cell signal curves for mice receiving TCR-I– and TCR-IV–transduced ChRLuc/OT-1/Rag^−/− CD8⁺ T cells represent a mean of four mice, and one mouse for mock. Error bars correspond to SD. One representative mouse for each treatment is shown at days 1 and 10 after ATT. One representative experiment out of three is shown. (B) The histograms depict three peptide-pulsed CD45.1⁺ gated splenocyte populations (no peptide, pI, and pIV) with low, intermediate, and high CFSE concentration. C57BL/6 mice that were either immunized with 16.113 cells 1 wk before the experiment or left untreated, and a TCR-IV–treated Rag^−/− mouse with recurrent 16.113p tumor (TCR-IV), are shown. The specific pIV kill of individual mice for each group is shown in the chart below the histograms (n = 3 for C57BL/6; n = 4 for C57BL/6 imm; n = 5 for TCR-IV).