Figure 4.

Administration of a STING agonist exacerbates DSS-induced colitis. Sections were harvested from DSS-treated WT mice that were co-treated with (a) 5 mg/kg/day of DMXAA or from (b) WT or (c) Tmem173^gt mice co-treated with 10 mg/kg/day of DMXAA every other day. (d) Inflammation-as assessed using the histological activity index (HAI), an index that provides a damage score-in the WT mice that were administered DMXAA was more severe than that of DMXAA-treated Tmem173^gt mice. Note the loss of the epithelial brush border (black arrowheads) and goblet cells (yellow arrowheads). Colonic damage in the Tmem173^gt mice co-treated with DMXAA was markedly reduced when compared to both WT groups. Sections were harvested on day 7. PAS stain. All sections imaged using a 20x objective; black bars at the bottom left of the panels represent 200 μM. Statistical significance was assessed by one-way ANOVA followed by Tukey’s multiple comparisons post-hoc test between all groups. Values for (D) are the means ± SEM, n ≥ 7 mice per group, ***P < 0.001 relative to both the WT(5) and WT(10) groups of mice.