Regulation of TLR9/10 expression by CpG DNA. Purified resting tonsillar B lymphocytes were stimulated in vitro for the indicated time periods (2 × 10⁹ cells/L) with CpG (6 μg/mL). Total RNA was prepared, converted to cDNA, and analyzed for expression of (A) TLR9 and (B) TLR10 by real-time PCR as outlined in “Materials and methods.” β-Actin expression was used to standardize all results. Results are expressed as copy number × 10⁶/μg RNA added to the cDNA synthesis reaction and represent the mean ± SEM (n = 3) for a representative experiment. These results are representative of 3 independent experiments.