Homeostatic Regulation of Salmonella-Induced Mucosal Inflammation and Injury by IL-23
Figure 3
IL-17 has cytoprotective activity during Salmonella induced injury.
(A) Changes in IL-17A, (B) IL-22 (C) Reg3γ gene expression elicited 3d after oral PBS (mock) or S. Typhimurium (Stym) infection in the ceca of WT, p19−/−, p35−/−, p40−/− mice were measured by qPCR. Data are expressed as the ratio of mRNA levels of the gene of interest divided by GAPDH expression from the same RNA. Pooled data from 3 separate experiments are shown. (D) Cecum and (E) liver were collected from IL-17RC−/− and C57BL/6 mice congenic for Slc11a1G169/G169 three days post infection. Organ homogenates were diluted and plated to determine CFU/organ. Bars represent the median bacterial load from two experiments. (F) Histological changes and (G) basal cell death at 3 d post-infection from infected WT and IL-17RC−/− H&E stained cecal sections were done as described in Fig. 2. (H) 20× magnification of TUNEL-positive (brown) cells of representative infected cecal sections. Bar in (H) represents 50 micron. (I) TUNEL positive cells were quantified per high-power field in the cecal sections from a minimum of 3 infected mice and two experiments. Statistical significance was determined using one way ANOVA with Bonferroni post test for A-C, Mann Whitney for D&E, and unpaired Student's t-test for F, G & I. *: p<0.05, **: p<0.01, ***: p<0.001.