FIG. 3.

The wild-type strain FAM20 (black bars) and the LOS-deficient lpxA mutant (white bars) induce similar levels of proinflammatory cytokines in serum of B6 and MyD88^−/− mice. (A) IL-6 induction in B6 and MyD88^−/− mice at various times postadministration (intraperitoneal) of 1 × 10⁸ FAM20 cells/mouse or equivalent amounts of biological material of the lpxA mutant. (B) TNF induction was measured at 1 h postadministration, and (C) KC levels were monitored at 8 h postadministration in serum. Both TNF and KC were significantly decreased in MyD88^−/− mice; however, no difference was observed in the response to the wild-type strain FAM20 and the lpxA mutant. Statistically significant reductions of IL-6 compared to FAM20 are indicated by bars, and significance compared to the control B6 mice at each time point is indicated by a single asterisk when P is <0.05. Significance between treatments was determined using an unpaired Student's t test. Data are represented as means ± standard deviation.