title: Elevated levels of macrophage inflammatory protein 2 in severe murine peritonitis increase neutrophil recruitment and mortality.
abstract: We hypothesized that chemokines may play important roles in a cecal ligation and puncture (CLP) model of septic peritonitis in CD-1 mice. Concentrations of C-X-C (macrophage inflammatory protein 2 [MIP-2] and ENA-78) and C-C (MIP-1alpha and JE) chemokines were measured (by enzyme-linked immunosorbent assay) in serum, peritoneal lavage fluid, lung, and liver at 4, 8, 24, 48, and 96 h after CLP. Significant elevations in all measured chemokines occurred in peritoneal fluid after CLP (P < 0.05). MIP-2, in particular, increased dramatically (>400-fold, P < 0.001) in peritoneal fluid, serum, and to a lesser extent lung and liver (P < 0.05). Increased MIP-2 was correlated with severity of sepsis (P < 0.001). To determine the significance of this finding, mice were passively immunized prior to CLP with polyclonal antibody to MIP-2, which decreased mortality from 85 to 38% at 96 h (P < 0.01). To further understand the mechanism of the effect of MIP-2, additional measurements demonstrated that anti-MIP-2 prior to CLP decreased the percent neutrophils in peritoneal fluid (55% +/- 12%, compared with 82% +/- 10% in controls), but no significant changes in tumor necrosis factor alpha, interleukin-6, or interleukin-10 occurred. MIP-2 contributes to the inflammatory response and overall mortality in this model of severe septic peritonitis, possibly by increasing recruitment of neutrophils, which clear bacteria but may also injure the host.
authors.affiliation: Pulmonary Research Laboratory, University of British Columbia, Vancouver, Canada.
authors.forename: K R
authors.initials: KR
authors.lastname: Walley
authors.forename: N W
authors.initials: NW
authors.lastname: Lukacs
authors.forename: T J
authors.initials: TJ
authors.lastname: Standiford
authors.forename: R M
authors.initials: RM
authors.lastname: Strieter
authors.forename: S L
authors.initials: SL
authors.lastname: Kunkel
mesh_terms: D000818:Animals; D054426:Chemokine CXCL2; D004195:Disease Models, Animal; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D051379:Mice; D015846:Monokines / Q000378:metabolism*; D009504:Neutrophils / Q000276:immunology*; D010529:Peritoneal Cavity / Q000166:cytology; D010538:Peritonitis / Q000503:physiopathology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D054426:Chemokine CXCL2; D015850:Interleukin-6; D015846:Monokines; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10