(a–c) Enzyme-linked immunosorbent assays for a) phospho-EGFR, b) EGF, and c) IL-1β on SI epithelium from uninfected C57BL/6 mice or C57BL/6 mice infected with 5×107 CFU ΔinvG or wildtype Salmonella 2 days earlier. (d) Density of GAPs in C57BL/6 mice one hour after i.p. injection or luminal injection of vehicle or 100 ng recombinant IL-1β. e) Density of SI GAPs in C57BL/6 mice 2 days after oral PBS or 5×107 wildtype Salmonella and daily injection with vehicle or 10 μg/kg of pan-caspase inhibitor (Z-VAD-FMK). (f) Density of GAPs in C57BL/6 or IL1r−/− mice, given 5×108 CFU of wildtype Salmonella in the SI lumen 1 hr earlier (left panel) or given 5×107 CFU wildtype Salmonella orally 2 days earlier. Data presented as the mean ± SEM, *p<0.05, ns-not significant. n=5 or more mice with 60 or more villi cross sections evaluated for each condition.