Decreased expression of early inflammatory mediators in response to challenge of sensitized IL-1R−/− mice. Groups of wild-type C57BL/6 and B6.IL-1R−/− mice were sensitized and challenged with DNFB. Challenged areas of skin and skin from naïve nonchallenged mice were excised 6 hrs. after challenge, snap-frozen, and homogenized. Whole cell RNA was prepared and was used to assess mRNA expression of TNF- α, IL-17, IFN- γ, and ICAM-1 in the skin samples by quantitative RT/PCR. The mean expression level for each of 4 samples per group ± SEM is shown. The results are representative of two individual experiments. *p ≤ 0.05.