Mage-3 and influenza-matrix peptide-specific cytotoxic T cells are inducible in terminal stage HLA-A2.1(+) melanoma patients by mature monocyte-derived dendritic cells

Dendritic cell (DC) vaccination, albeit still in an early stage, is a promi sing strategy to induce immunity to cancer. We explored whether DC can expa nd Ag-specific CD8(+) T cells even in far-advanced stage IV melanoma patien ts. We found that three to five biweekly vaccinations of mature, monocyte-d erived DC (three vaccinations of 6 x 10(6) s.c. followed by two i.v. ones o f 6 and 12 x 10(6), respectively) pulsed with Mage-3A2.1 tumor and influenz a matrix A2.1-positive control peptides as well as the recall Ag tetanus to roid (in three of eight patients) generated in all eight patients Ag-specif ic effector CD8(+) T cells that were detectable in blood directly ex vivo. This is the first time that active, melanoma peptide-specific, IFN-gamma -p roducing, effector CD8(+) T cells have been reliably observed in patients v accinated with melanoma Ags, Therefore, our DC vaccination strategy perform s an adjuvant role and encourages further optimization of this new immuniza tion approach.