IL-1R signaling is required for the exaggerated IEC responses in <i>Sigirr −/−</i> mice.

<p>The cecal tissues from infected <i>Sigirr −/−</i> mice show increased abundance of IL-1α gene transcripts (A) as compared to WT mice. The <i>Sigirr −/−</i> mice also express increased levels of IL-1β protein in their cecal tissues under uninfected and <i>C. rodentium</i> infected conditions as measured by (B) ELISA and (C) Western blot. <i>Il-1r/Sigirr −/−</i> mice exhibit increased (D) mortality rates, (E) elevated pathogen burdens and (F) severe mucosal damage. The severe damage suffered by the <i>Il-1r/Sigirr −/−</i> mice was accompanied by impaired IEC proliferation as shown by (G) immunostaining for Ki-67 and by higher IEC permeability as quantified by (H) FD4 in serum. Pathogen counts represent mucosal associated bacteria. Results are pooled from 2–4 independent infections with n = 3–4 per group. Error bars = SEM, (Student t test (Figure A, B, E), one-way ANOVA (Figure G, H), *P<0.05, **P<0.01). Images were taken at 200× magnification.