Figure 2: Genetic deficiency of IL-22 results in more severe EAU and EAE.
IL-22 knockout (KO) mice and their wild type littermates (WT LTM) were immunized with IRBP protein and human IRBP peptide 1-20. (A) Shown are average disease scores of both eyes of individual mice on day 21 p.i. from four separate experiments. Data were analyzed by Mann-Whitney U test (p = 0.002). (B) Histopathology of EAU eyes in IL-22 deficient (Knockout) and WT Littermate mice. Thickening of retinal layers and destruction of retinal architecture is more pronounced in the IL-22 knockout mice compared to their WT littermates. Original magnification of the image is x200. (C-D) Antigen induced T cell memory response and cytokine production are enhanced in IL-22 knockout mice. (C) Lymphocytes from IL-22 KO mice showed significantly higher antigen specific memory immune response (lymphocyte proliferation assay with IRBP for 72 hours) compared to that of WT Littermates. Shown is one of two independent experiments. Differences between groups were analyzed using 2-way ANOVA. (D) A non-significant increase in pro-inflammatory cytokines was observed in the IL-22 KO mice. Draining lymph node cells were cultured with 20μg/ml IRBP for 48 hours and culture supernatants were collected for multiplex cytokine assay (Bioplex) using the Luminex system (BioRad). Shown is data from one of two independent experiments. (E) IL-22 KO mice and their wild type littermates were immunized with MOG35-55 for inducing EAE and severity of disease was scored daily. Differences between strains were analyzed by two-way ANOVA. Shown are pooled data from three independent experiments.