PTO-modified immunostimulatory ORNs activate lymphocytes and DCs in vivo. Mice were injected intravenously with 20 μg ORN 9.2dr, 9.2dr PTO, PolyA, or PolyA PTO and splenocytes were isolated 18 hours after injection. CD69 expression was examined on CD4⁺ and CD8⁺ T cells and on B cells (B220⁺, CD11c⁻) (A,B) and on MDCs (CD11c⁺, CD11b⁺, B220⁻; MDC) and PDCs (CD11c⁺, CD11b⁻, B220⁺; PDC) (C). (A) Representative data from one of 5 experiments are gated on CD8⁺, CD4⁺ T cells or B cells, respectively. Numbers indicate the percent of gated lymphocytes that are CD69⁺. (B-C) Data show the mean of individual mice in one experiment (PolyA: n = 3, all other groups: n = 4) ± SEM. Results are representative of 5 independent experiments. *P < .001; ns indicates not significant. The asterisk without brackets indicates comparison to unstimulated group. The significance level was the same for all cell populations analyzed.