(A) Similar TAg expression in HCC lines derived from Ad.Cre-treated LoxP-TAg mice and LoxP-TAg × Alb-Cre mice. Western blot analysis of TAg expression in primary HCC lines derived from Ad.Cre-treated LoxP-TAg mice (Ad.56, Ad.451, Ad.434) and LoxP-TAg × Alb-Cre mice (Alb.7, Alb.14). Sporadic TAg⁺ tumor line 16.113 was used as a control. 20 μg protein was separated by SDS-PAGE gel, blotted onto nitrocellulose membrane, and incubated with anti-TAg antibodies. After autoradiography, the membrane was stripped and reprobed with anti–β-actin antibodies as loading control. The lanes were run on the same gel but were noncontiguous. (B) TAg⁺ HCC lines induced pIV-specific CTLs. 1 × 10⁶ cells of tumor lines 16.113 and HCC lines as indicated were injected s.c. into B6 mice, and 10 days later pIV-specific in vivo kill was assays were performed as in Figure 3. The percentage of specific killing of peptide-loaded cells is indicated. Each symbol represents 1 mouse; bars indicate mean values. The P value represents overall significance of the graph calculated by Krusal-Wallis test. In a separate experiment, 1 × 10⁶ TAg⁺ HCC cells and, as a control tumor line, 16.113 cells, were injected s.c. into untreated 8- to 12-week-old Rag-2–deficient and immunocompetent B6 mice. Tumor growth was followed using calliper measurement. Shown is the number of mice that rejected challenge tumor per mice in experiment. Mice were observed until challenge tumors grew up to an average size of at least 10 mm in diameter. Mice that rejected the transplanted tumor cells were observed for at least 90 days.