(A, B) Immunoblot analysis (A) and quantification (B) of pro-caspase-1 (p45) and cleaved caspase-1 (p20) in colon tissue from germ-free and SPF mice.
(C–E) IL-18 production by colon explants from germ-free mice (C), antibiotics-treated mice (D), and during early stages of post-natal colonization (E).
(F) Differential expression between wild-type (WT) and Il18−/− mice of antimicrobial peptides (AMPs) versus all other genes. Box = interquartile range (IQR) = 25th to 75th percentile, line - median, star - mean, whiskers - IQR*1.5. Mann-Whitney U-test p<0.0001.
(G–O) Expression levels of the indicated AMPs in WT and Il18−/− colonic tissue (G–I), during early stages of post-natal colonization (J), in the colon of bone marrow chimeras generated from WT and Il18−/− mice (K), in colonic explants from germ-free mice cultured with IL-18 compared to controls (L), in IL-18 injected germ-free mice compared to SPF controls (M, N), and in colonic explants cultured with or without the NF-κB inhibitor Bay 11–7085 (O).
Data are expressed as mean ± SEM. * p<0.05; ** p<0.01; *** p<0.001.
Pairwise comparison was performed using Student’s t test, unless stated otherwise.
Results shown are representative of 3 (panels A–D) or two (panels E–O) independent repeats (n= 3–13 per group).
See also Figure S1.