title: Interleukin-18 facilitates the early antimicrobial host response to Escherichia coli peritonitis.
abstract: To determine the role of endogenous interleukin-18 (IL-18) during peritonitis, IL-18 gene-deficient (IL-18 KO) mice and wild-type mice were intraperitoneally (i.p.) infected with Escherichia coli, the most common causative agent found in septic peritonitis. Peritonitis was associated with a bacterial dose-dependent increase in IL-18 concentrations in peritoneal fluid and plasma. After infection, IL-18 KO mice had significantly more bacteria in the peritoneal lavage fluid and were more susceptible for progression to systemic infection at 6 and 20 h postinoculation than wild-type mice. The relative inability of IL-18 KO mice to clear E. coli from the abdominal cavity was not due to an intrinsic defect in the phagocytosing capacity of their peritoneal macrophages or neutrophils. IL-18 KO mice displayed an increased neutrophil influx into the peritoneal cavity, but these migratory neutrophils were less activate, as reflected by a reduced CD11b surface expression. These data suggest that endogenous IL-18 plays an important role in the early antibacterial host response during E. coli-induced peritonitis.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000008:administration & dosage; D039481:CD11b Antigen / Q000378:metabolism; D018925:Chemokines / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D004927:Escherichia coli Infections / Q000276:immunology* / Q000473:pathology; D005260:Female; D020382:Interleukin-18 / Q000172:deficiency / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D008099:Liver / Q000293:injuries; D055370:Lung Injury; D017737:Macrophages, Peritoneal / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009504:Neutrophils / Q000276:immunology; D010538:Peritonitis / Q000276:immunology*; D010587:Phagocytosis; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D000906:Antibodies; D039481:CD11b Antigen; D018925:Chemokines; D016207:Cytokines; D020382:Interleukin-18; D011994:Recombinant Proteins