Peptide-specific CTL responses induced in vivo (patient no. 2) by immunizations with HER-2/neu peptide-pulsed DCs.

DCs were pulsed with the synthetic peptides derived from HER-2/neu and incubated with PBMNCs obtained before (C,D) or after 3 vaccinations with E75 (▪, A,C) or GP2 (▪, B,D) peptides to assess a MHC class I–restricted CTL response in vitro. Cytotoxic activity of induced CTL was determined after one restimulation in a standard⁵¹Cr-release assay using A498 (HLA-A2⁺/HER-2/neu⁺, ●) and T-2 (HLA-A2⁺) cells as targets pulsed for 2 hours with 25 μg of the cognate peptide (▪) or irrelevant HIV peptide (■). K562, ▴; Croft cells (▿); SK-OV-3 cells (○).