pDCs are efficient stimulators of CD8 T-cell proliferation and Tc1 differentiation. (A) FACS plots depict the gating used and the proportion of divided (CFSE^low) CD8 or CD4 T cells in a mixed leukocyte assay at a DC:T cell ratio of 1:50. Naive T cells were enriched and cocultured with pDCs or mDCs prestimulated with AT-2–inactivated SIVmac251 (AT-2 SIVmac251) at a DC:T cell ratio of 1:50 or 1:20 in a mixed leukocyte assay. Bar charts show fold increase in CFSE^low CD8 or CD4 T cells induced by blood-derived DCs prestimulated with AT-2 SIVmac251. Each number represents an individual experiment. ND indicates not done. (B) Bar charts show fold increase in CFSE^low CD8 or CD4 T cells induced by MLN-derived pDCs prestimulated with AT-2 SIVmac251. (C) FACS plots depict gating for IFN-γ+ CD8 T cells. Bar charts show cell counts of IFN-γ+ CD8 or CD4 T cells stimulated with anti-CD3 in the presence or absence of blood-derived DCs stimulated with AT-2 SIVmac251at a DC:T cell ratio of 1:50. These cell counts represent the difference between DC and no DC controls. Each number represents an individual experiment.