DCs cultured with live B16 cells induced a complete protection against tumor and a strong IFN-γ response. Five C57BL/6 mice per group were immunized twice (days 0 and 14) with DCs cultured with LPS and either medium alone, or gp100_25-33 and TRP2_181-188 (peptides), or live B16 cells (B16 z-VAD), or apoptotic B16 cells (B16γ). After culture, DCs were purified, irradiated, and injected. On day 21, mice were challenged with B16 cells intravenously 2 weeks later, lung tumors were counted (A), and splenocytes were restimulated with B16 cells or culture medium (c.m.) and tested in an IFN-γ ELISPOT (B). Splenocytes were also restimulated with phorbol myristate acetate and ionomycin before surface labeling, and then intracellular labeling with IFN-γ mAb (solid lines) or isotype control (dotted lines). Events were gated on CD3⁺CD8⁺ (C) or on CD3⁺CD4⁺ (D) splenocytes. **P < .01. n.s. indicates not significant. Data are mean ± SEM of 5 mice per group.