Immunization with stressed apoptotic 12B1-D1 cells induces tumor-specific CTLs.

BALB/c were immunized with Mit-C–treated 12B1-D1 cells that were mixed with 20 μg/mouse liver lysate, liver-derived HSP70, or CRCL on days −14 and −7. For controls, mice were immunized with an equal number of Mit-C–treated 12B1-D1 cells or saline. On day −2, splenocytes of the immunized mice were harvested and cocultured with Mit-C–treated 12B1-D1 cells for 5 days. Stimulated effector cells were tested for (A) cytolytic activity against 12B1-D1 cells, (B) parental 12B1 cells, or (C) A20 cells by nonradioactive cytotoxicity assay. Representative data from 1 of 3 experiments are shown.