Generation of DKK1 peptide-specific CTL lines. Shown are proliferative responses, measured by [³H]thymidine incorporation, of a T-cell line specific for P20 (A) or P66v (B) in response to pulsed (P20-DC or P66v-DC) or unpulsed autologous DCs, or (C) cell proliferation, measured by CFSE dilution, of a T- cell line specific for P20 or P66v generated from a HLA-A*0201⁺ blood donor in response to unpulsed DCs or DCs pulsed with P20 or P66v peptides. Percentages shown are the frequency of dividing CD8⁺ T cells. (D) HLA-A*0201 peptide-tetramer staining showing the frequency of DKK1 peptide-specific CD8⁺ T cells obtained from a HLA-A*0201⁺ blood donor in cultures during in vitro stimulations. Percentages of cells are shown. Similar results were obtained with T-cell lines from other 2 HLA-A*0201⁺ blood donors and 3 patients with myeloma. Cytotoxicity of T-cell lines specific for P20 (E) or P66v (F) against autologous primary myeloma cells (MM) and HMCLs U266 and ARP-1. These cell lines were generated from a patient with myeloma. Representative results of 3 independent experiments are shown. Error bars show SD.