IL-18 modulates the onset of S.Tm-induced intestinal inflammation.

(a) Mature IL-1β and IL-18 protein levels were measured in whole cecum tissue homogenates from C57BL/6 WT mice. Mice were Sm-pretreated and remained uninfected or were infected orally with 5x10⁷ CFU S.Tm for 12h (n = 7 per group); dashed lines indicate the detection limit. (b and c) Il1ab^-/- and Il18^-/- mice and littermate controls were Sm-pretreated and infected orally with 5x10⁷ CFU S.Tm for 12h (n = 6–9 per group). (b) pathological score; arrows indicate representative mice depicted in panel c, (c) HE-stained cryosections from representative mice of each group; SE = submucosal edema, L = lumen; scale bar = 100μm; left panel: Il1ab^-/-, right panel: Il18^-/-. (d and e) Casp1/11^-/- and Casp11^-/- mice and littermate controls were Sm-pretreated and infected orally with 5x10⁷ CFU S.Tm for 12h (n = 5–7 per group). (d) Mature IL-18 protein levels in whole cecum tissue lysates from Casp1/11^-/- or Casp11^-/- mice and littermate controls; dashed lines indicate the detection limit. (e) Pathological score. (f) C57BL/6 WT mice were Sm-pretreated, injected intraperitoneally with rIL-18BP or PBS, infected orally with 5x10⁷ CFU S.Tm for 12h (n = 5 per group) and mucosal inflammation was quantified. (g) C57BL/6 WT mice were Sm-pretreated, injected intraperitoneally with rIL18 or PBS, infected orally with 5x10⁷ CFU S.Tm for 8h (n = 9 per group) and mucosal inflammation was quantified. Data represent the mean ± SD and statistical analysis was performed using the Mann-Whitney-U test (ns = not significant, *: p<0.05; **: p<0.01; ***: p<0.001).