Rapid and long-lasting cytokine deregulation upon triggering TLR7. Mice were bled from the tail vein, and cytokine levels were measured using a multiplexed particle-based flow cytometric cytokine assay. (A) Rapid cytokine deregulation. Cytokine levels were measured before (baseline, BL), 90 minutes after the first injection, and on day 3 of repetitive treatment. IL-12p40 levels were measured 6 hours after a single dose and on day 7 of repetitive treatment. (B) Long-lasting cytokine deregulation. Mice were treated daily at indicated concentrations, and cytokine levels were monitored over time (ie, on days 7, 21, and 42 of treatment). (C) Cytokine deregulation is TLR7 dependent. C57BL/6 and knockout mice were treated with 1 mg/kg per day of R848 for 7 days. Cytokine levels at day 0 (left bars) and at day 7 (right bars) are shown. Mean values from mock- and R848-treated animals at analogous time points were compared using unpaired t-test. Error bars indicate standard error. N ≥ 3.