Fig. 4: OIT protects against gastrointestinal damage associated with inflammatory arthritis in both symptomatic and asymptomatic cases.

Naïve, CIA and OIT asymptomatic mice and OIT symptomatic mice were culled at day 33 when gut tissue and total mesenteric lymph nodes (MLNs) were collected. a Isolated gastrointestinal tract from a naïve mouse showing the four anatomical areas used for further study. b Duodenum, jejunum, ileum, and colon were fixed, and tissue sections were subjected to hematoxylin and eosin staining. The length of villi and crypts was measured using Image J software, and the ratio of villi/crypt was quantified. Each dot represents the villi/crypt ratio for individual mice, and data were collated from two independent experiments. Statistical significance was evaluated by ordinary one-way ANOVA, where *p < 0.05, **p < 0.01 and ***p < 0.001. c Colon tissue sections were stained with PAS to detect changes in the mucus layer and associated pathology. Scale bars = 500 μm. The depicted mice are representative of individual mice whose disease scores fall within the median value for each group. d MLNs were collected to generate single-cell suspensions, and a total number of cells was counted. Cell number and percentage of B cells, total T cells, CD4 and CD8 T cells were evaluated by Flow Cytometry. Each dot represents one individual mouse and error bars show mean ± SEM. Mice were pooled from 2 independent experiments. Statistical significance was determined using Ordinary one-way ANOVA. Significance is indicated by asterisks, *p < 0.05, **p < 0.01.