Activation of primary DC types does not enhance MHC class II presentation of NY-ESO-1. (A) CD1c⁺ PBDCs were pulsed with NY-ESO-1 protein, NY-ESO-1/IC, or NY-ESO-1/IMX at the indicated concentrations and cultured overnight with GM-CSF in the absence (•) or presence of R-848 (▴) or CD40L (▪) before coculture with NY-ESO-1–specific CD4⁺ T cells. IFN-γ production by CD4⁺ T cells was quantified by ICS. Data are representative of 4 experiments. (B) Plasmacytoid DCs were pulsed with NY-ESO-1/IC and cultured overnight with IL-3 in the absence (•) or presence of CD40L (▪), R-848 (▴), or CpG ODN2006 (▵) before coculture with NY-ESO-1–specific CD4⁺ T cells. Data are representative of 2 experiments.