Therapeutic immunity of DC vaccines pulsed with various tumor cell lysates, against B16 melanoma. (A) Schematic representation for vaccination. C57BL/6 mice were challenged subcutaneously with 1 × 105 B16 cells and vaccinated with different preparations of TCL-pulsed DCs when the tumor volume reached to 50-80 mm3. On day 10 after the secondary boosting, splenocytes were harvested for cytotoxic T lymphocyte activity (CTL) assay. (B) CTL activities in test mice. Splenocytes from vaccinated or control group mice (n = 8 mice per group) were collected and CTL activity assayed with target tumor cells. Test DCs were pulsed with TCL-DMSO, TLC-DX, TLC-C, or TCL-CMQ. PBS-treated mice (Ctrl) did not receive DC vaccine, only a PBS injection. Test mice in the mature DC group (maDC) were subjected to vaccination with unpulsed mature DCs. (C) Tumor growth of treated mice. Tumor size of each group (n = 8 mice per group) was measured on indicated days. (D) Survival rates of treated mice. Survival of mice (n = 12 mice per group) was observed after tumor challenge. For all experiments, the TCL-FMQ groups showed a similar pattern of activities as that of TCL-CMQ and hence the data are not shown. All data are expressed as mean ± S.E.M.