<i>C. jejuni</i> induces TLR-dependent acute enterocolitis in gnotobiotic IL-10^−/− mice.

<p>Gnotobiotic IL-10^−/− (B10 background) as well as TLR-2^−/− IL-10^−/− and TLR-4^−/− IL-10^−/− mice were generated by antibiotic treatment and orally infected either with <i>C. jejuni</i> B2 (Cj; solid symbols) or a commensal <i>E. coli</i> strain (Ec; crossed symbols) derived from the commensal gut microbiota of conventional colonized wildtype mice as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040761#s4" target="_blank">Methods</a>. (<b>A</b>) Disease activity of infected mice and (<b>B</b>) histopathological changes in HE-stained colonic paraffin sections applying a standardized clinical and histopathological score, respectively, were determined at day 7 p.i., illustrated by (<b>C</b>) representative photomicrographs out of three independent experiments (100x magnification, scale bar 100 µm) derived from <i>C. jejuni</i> B2- (upper panel) and <i>E. coli</i>- (lower panel) infected IL-10^−/− (left panel), TLR-2^−/− IL-10^−/− (middle panel), and TLR-4^−/− IL-10^−/− (right panel) mice. Solid arrows indicate mucosal, dotted arrows submucosal iinfiltrates, black arrow heads ulcerations, white arrow heads crypt drop-out, and gray arrow heads mucosal bleeding. Numbers of analyzed animals are given in parentheses. Medians (black bars) and significance levels (<i>P</i>-values) determined by Mann-Whitney-U test are indicated. Data shown are representative for three independent experiments.