Figure 3.

Bacterial penetration at tissue is greater in mice lacking IL-1 and/or TNF activity. The number of bacterial colonies that could be cultured from the apical portion of the distal root 8 days after exposure and inoculation with six oral pathogens was determined. Values represent the mean ± SEM, n = 10 for each group. All receptor-mutant mice showed significant differences (P < 0.01) when compared with wild-type mice. **Significantly (P < 0.01) larger values were observed in TNFRp55^−/−-IL-1RI^−/− mice compared to IL-1RI^−/− and TNFRp55^−/−-p75^−/− mice. *IL-1RI^−/− and TNFRp55^−/−-p75^−/− mice had values that were not significantly different from each other (P > 0.05) but were significantly higher than those of wild-type mice (P < 0.01).