In vivo maturation of neonatal DCs. Seven-day-old mice were intraperitoneally injected with 100 μg CpG-ODN (bold line) or control ODN (gray histogram). Three hours later, spleen DCs were purified and analyzed by FACS for MHC II, CD40, CD86, and CD25 expression. Dashed line corresponds to isotypic control mAb on DCs purified from CpG-ODN–injected mice. Data are representative of 3 experiments.