MPL and CpG-ODN increase the numbers of activated DCs in draining LNs. Kinetics of frequencies of pDCs (A) and mDCs (B) were defined within the cells isolated from LNs by flow cytometry, as described in supplemental Figure 2. Statistical analysis indicates a significant change of cell frequency relevant to the baseline. Data are means ± SEM. *P < .05; **P < .01; ***P < .001 by t test. Activation and maturation profiles were measured by assessing the expression of the surface markers CCR7, CCR5, CD80, and CD86 at days 1 and 3 after TLR-L injection. Histograms represent the isotype control (gray), baseline at day −12 (black) and day 1 (green) and day 3 (red) after TLR-L injection. A single representative animal is shown for each experimental group. (C) Immunohistochemistry staining was performed on frozen LN sections for evaluating the in situ localization of APCs in the animals injected with CpG-ODN (days 1 and 3). Cells were assessed by CD123 (red) and CD11c (green) staining; B-cell follicles were visualized by CD20 staining (blue). One representative animal from the CpG-ODN experimental group is represented.