Immunotransplantation cures mice with large tumors. (A) Donor mice received no treatment or CpG/CTX vaccination. Recipient mice were challenged with 10⁷ A20 cells subcutaneous 14 days earlier, then received either no irradiation or 900 cGy of TBI followed by 5 × 10⁶ BM cells and splenocytes from donors. Nonirradiated mice also received an intravenous boost of A20 cells stimulated with CpG followed by irradiation (CpG-A20 cells) at the time of transplantation. (B) On day 15 after transplantation, mice were bled, and IFN-γ–producing tumor-specific CD8 T cells were assayed by flow cytometry as described (n = 3). (C) Cohorts of mice (n = 10) were followed for bidimensional tumor size, and proportions of tumor-free mice are indicated. Three mice from the “no vaccine donor” cohort died within 3 days after transplantation, still with palpable tumor. (D) Tumor (400-mm²)–bearing mice were used as immunotransplantation recipients as in panels A to C from donors receiving no treatment or CpG/CTX vaccination; shown are photographs of the same mice over time. (E) Tumor (100 mm²)–bearing mice were used as immunotransplantation recipients and were killed on day 8 after transplantation. Excised tumors were stained for CD3 and visualized per standard immunoperoxidase protocol (original magnification ×20, representative of 10 fields examined).