Mature dendritic cells are superior to immature dendritic cells in expanding antigen-specific naïve and memory CD8+ T cells

For successful dendritic cell (DC)-based immunotherapy, it is critical to identify the most potent stage of human DCs, including immature DCs (imDCs) and mature DCs (mDCs). imDCs were obtained by culturing monocytes in the presence of GM-CSF and IL-4 for 5- 7 days and imDCs were further cultured for 24-48 h in the presence of TNFalpha, IL-6, IL-1beta and PGE2 to obtain mDCs. Melan-A- and EBV (BRF1) peptides were used and the frequency of antigen-specific CD8+ T cells was assessed using appropriate tetramers. mDCs were potent antigen-presenting cells for the induction and proliferation of antigen-specific naive and memory CD8+ T cells and may overcome regulatory functions that suppress antigen-specific CD8+ T cells. Our findings that mDCs can efficiently expand antigen-specific naive and memory CD8 + T cells have important implications in the development of vaccination strategies and support the use of antigen-loaded mature DCs in human clinical trials