ssRNA induces efficient DC activation in vivo. C57BL/6 mice were injected intravenously with the indicated TLR agonists. PolyU and polyUs21 were administered as complexes with DOTAP. Splenocytes were isolated and DC populations were analyzed by flow cytometry. (A) The up-regulation of the maturation marker CD86 on gated DC subsets was determined 4 hours after adjuvant administration. (B) The percentage of IFN-α– and IL-12p40–expressing PDCs was assessed by flow cytometry 4 hours after treatment. (C) The IL-12 p40 expression by PDC, CD4⁺, DN, and CD8α⁺ DC was analyzed as in panel B. The data are representative of 3 independent experiments (A-B) or are compiled to one figure with the SEM depicted (C).