Immunotransplantation-induced tumor immunity increases with time and with serial transplantations. (A) Donor mice received CpG/CTX vaccination, and recipient mice received TBI. (B) Donor splenocytes and BM were transferred to recipients that received 900, 600, or 300 cGy as depicted. (C) Recipient mice received 900 cGy of TBI followed by 5 × 106 BM cells and splenocytes from donors at donor/recipient ratios of 1:1, 1:4, or 1:8, as depicted. (B,C) Recipient mice received high-dose tumor challenge on day 3 after transplantation and were followed for bidimensional tumor size. Proportions of tumor-free mice are indicated. (D) Serial immunotransplantation. Cured immunotransplantation recipients from experiments conducted as in panel A were subsequently used as donors in a serial immunotransplantation. Secondary recipients received either no irradiation or 900 cGy of TBI as depicted, followed by 5 × 106 BM cells and splenocytes from cured immunotransplantation mice. On day 3 after (secondary) transplantation, recipients were challenged with 107 A20 cells subcutaneously and (E) followed for tumor growth.
