Figure 3. IFNγ provides crucial defense in host against YE infection.

(A-D) lfng^−/− mice or control mice were infected orally with 1.5 × 10⁸ YE CFU. (A) Survival curves (n=18–19 per group). (B) Changes in body weight (n=5 per group). (C) Bacterial burdens (n=6–7 per group) at day 7 p.i. Bars show the mean, symbols represent individual mice. Dotted horizontal line represents the limit of detection. (D) Representative H&E-stained splenic sections at day 7 p.i. Scale bars, 100μm. Two independent experiments were carried out yielding similar results. (E) C57BL/6 mice were infected orally with 1.5 × 10⁸ YE CFU (n=5 per group). Absolute numbers of IFNγ-producing cells from ILC subsets from the SI-LP of uninfected (-YE) and Y. enterocolitica infected (+YE) mice were analyzed at day 3 p.i. Cells were stimulated for 4h with PMA and ionomycin (P/I) and brefeldin A (BFA) was added in the last 2h of incubation before analysis by intracellular cytokine staining. Statistical analysis was performed using Log-rank test (A), 2 way ANOVA with Bonferroni’s multiple hypothesis correction (B), or Mann-Whitney test (C,E). Statistical significance is indicated by *, p < 0.05; **, p < 0.01; ***, p < 0.001. Data in B and D show mean±SEM. Data represent pooled results from two experiments (A) or representative results of at least two independent experiments with five mice in each experimental group (B-E). See also Figure S3.