CTL priming by CD8(+) and CD8(-) dendritic cells in vivo

Two distinct developmental pathways are driving the formation of myeloid- a nd lymphoid-related dendritic cells (DC) which differ in anatomical localiz ation and phenotype. In terms of function, it has been hypothesized that on ly the myeloid-related CD8(-) DC are able to initiate immune responses, whe reas the lymphoid-related CD8(+) DC have been suggested to induce tolerance . Here we show that both subsets activate CD8(+) T cells in vitro and induc e protective anti-viral CTL responses in vivo. Thus, vaccine strategies usi ng peptide-pulsed DC do not have to take into account DC subsets for primin g.