OK432 mediates its effect via TLR3 by a ligand that needs RNA and protein present.

<p>OK432 was pre-treated with RNase A and protease K for 30 minutes at 37°C before being diluted 25-fold and added to the DC. The pre-treatment was performed with 100, 10 and 2 µg/ml protease K, and RNase A was tested at 100, 10 and 1 µg/ml. After 24 hours the supernatants were analyzed for presence of IL-12p70. The amount produced is displayed as a percentage compared to that of OK432 alone set to 100%. Protease K treatment diminished IL-12p70 production in a dose-dependent manner. RNase reduced the IL-12p70 production by more than 50%, while the combination of protease K and RNase treatment reduced the IL-12p70 production by around 90%. IL-12p70 production was rescued by adding a RNase inhibitor together with the pre-treatment. For each treatment, the mean and SEM is shown (N = 2–4 experiments).