Both liver-derived and 12B1 tumor–derived CRCL enhance the immunogenicity of Mit-C–induced apoptotic tumor cells.
12B1-D1 cells (2 × 106/mouse) were treated with 100 μg/mL Mit-C for 1 hour and then extensively washed. (A) The 20 μg/mouse liver–derived CRCL was added to the cells and the mixture was subcutaneously injected into the groin of BALB/c mice on days −14 and −7. Control mice were immunized with an equal number of Mit-C–treated 12B1-D1 cells alone or saline. On day 0, mice were challenged with 2 × 104 (LD100) 12B1-D1 cells subcutaneously. Mice that were vaccinated with saline or Mit-C–treated 12B1-D1 alone were killed on day 21, whereas mice that were vaccinated with apoptotic cells plus CRCL as adjuvant survived tumor-free up to day 80. (Saline versus 12B1-D1/Mit-CP = NS; saline, or 12B1-D1/Mit-C versus 12B1-D1/Mit-C + CRCL P < .05 from day 15 onward; n = 8 mice per group. Representative data from 1 of 4 experiments are shown.) (B) The 20 μg/mouse liver– or 12B1 tumor-derived CRCL was added to the cells and the mixture was subcutaneously injected into the groin of BALB/c mice on days −14 and −7. Control mice were immunized with saline. On day 0, mice were challenged with 2 × 104(LD100) 12B1-D1 cells subcutaneously. Mice that were vaccinated with saline or Mit-C–treated 12B1-D1 alone were killed on day 23, whereas mice that were vaccinated with apoptotic cells plus CRCL as adjuvant survived tumor-free up to day 56. (Saline versus CRCLP < .05 from day 15 onward; n = 8 mice per group. Representative data from 1 of 2 experiments are shown.)
