Perforin-deficient mice fail to elicit overt gut inflammation by 12h p.i.

(a and b) Prf1^-/- mice and littermate controls were Sm-pretreated and infected orally with 5x10⁷ CFU S.Tm for 12h. (a) Pathological score; arrows indicate representative mice depicted in panel b, (b) HE-stained cryosections from representative mice of each group. (c) Il18^-/- mice and littermates or (d) Prf1^-/- mice and littermates were Sm-pretreated and infected orally with 5x10⁷ CFU S.Tm-pssaG-GFPmut2 for 12h (n = 4–6 per group). S.Tm cecum tissue counts were determined per 20μm cross-section. Statistical analysis was performed using the Mann-Whitney-U test (** = p<0.01).