Fig. 6: Expression of IL-22 in mesenteric lymph nodes and gastrointestinal tract.

Naïve, CIA and OIT asymptomatic mice were culled at day 33, when mesenteric lymph nodes (MLNs), ileum and colon samples were collected. Single-cell suspensions were obtained from MLNs and digested gut tissue, and IL-22 expression was subsequently evaluated by flow cytometry in total isolated cells (a–c) and specific cell populations, including CD4 T cells, CD8 T cells, B cells, group 3 innate lymphoid cells (ILC3), γδ T cells, NK cells and NKT cells (d–f). a–c Percentage and number of total IL-22+ cells in MLNs (a), ileum samples (b) and colon (c). Naïve n = 10. CIA n = 15, asymptomatic OIT n = 7. Each dot represents values for individual mice; bars show mean values for each group ± SEM. d–f Relative cell frequency and mean fluorescence intensity (MFI) of IL-22 in the indicated cell populations in MLNs (d), single cells isolated from the ileum (e) and colon (f). Each corner of the radar charts represents the indicated normalised parameter for naïve (grey), CIA (red) and asymptomatic OIT (orange) mice. Data were normalised to maximum expression in each group; naïve n = 5, CIA n = 5, asymptomatic OIT n = 4. g Ileum and colon sections were stained with anti-IL-22 antibodies and specific secondary antibodies (Red) and DAPI (Blue) as counterstaining. Scale bars = 500 μm. Pixel intensity for IL-22 staining was quantified using ImageJ, each dot shows the mean value of 10 different areas for each individual mouse. Error bars show standard error (SEM). Statistical significance was determined using raw data and ordinary one-way ANOVA, where *p < 0.05, **p < 0.01. h Detailed images of colon sections stained for IL-22, scale bars = 100 μm and 20 μm for zoomed areas.