Figure 8. Anti-tumor immunity of PDT-DC vaccine.

PECA cells were treated with ALA-PDT (0.5 mM ALA, 0.5 J/cm²) or three cycles of freeze thaw (F/T). Six hours after treatment, the cells were collected and incubated with imDCs for 24 h. SKH-1 mice were randomly divided into three groups (10 per group), immunized with PDT-DC vaccine, F/T-DC vaccine or PBS. Mice were then challenged with viable PECA cells in the right flank 7 days after the third immunization. No tumors were seen at the challenge site in the PDT-DC vaccine group, while all mice immunized with PBS or the F/T-DC vaccine experienced tumor growth after tumor cells challenge.