Fig. 4.

Effect of Sup ODN on proinflammatory cytokine production in mice treated with NNK plus silica. Mice were treated with NNK plus silica as described in Figure 1. They were then injected i.p. with PBS (N = 16), 300 μg of Sup ODN (N = 20) or 300 μg of control ODN (N = 16) once per week for 4 weeks, starting on day 0. TNFα and IL-1β mRNA levels were measured by reverse transcription–PCR on tissue homogenates at 4 months. Bars show cytokine mRNA levels relative to naive mice (all values normalized to GAPDH). Results from the PBS and control ODN-treated groups were indistinguishable and thus combined to increase statistical power. Each bar represents the mean ± SEM of data combined from three independent experiments. *P < 0.05, **P < 0.01.