Heparin binding protein increases survival in murine fecal peritonitis.

Abstract

To test the effectiveness of recombinant heparin-binding protein (HBP), a neutrophil-derived multifunctional protein with monocytic-specific properties, in fecal peritonitis and polymicrobial sepsis. Prospective, controlled animal trial. Animal research laboratory. Swiss Webster mice challenged with cecal ligation and puncture (CLP) and treated with recombinant HBP and 60 mg/kg cefoxitin twice a day. HBP was administered to mice at different concentrations and different intervals before and after CLP. Rat albumin (1%) was administered to control animals. MORTALITY RATE: Survival was increased in mice pretreated intraperitoneally 24 hrs before CLP with 10 microg or 100 microg of HBP without cefoxitin (p = .01, Cox-Mantel log-rank test). Compared with control animals, survival was increased significantly (from 5% to 47%, p = .014) in mice that received cefoxitin and 50 microg ip HBP immediately after CLP, followed by continuous administration of HBP (12 microg/24 hrs). Intravenous administration of HBP (0.1, 1, and 10 microg) at the time of CLP showed an opposite dose effect; low doses (0.1 microg) prolonged early survival, whereas high dose (10 microg) shortened survival (p = .036). Compared with control animals, overall survival was not different. CHEMOTAXIS: Cytospin preparations from peritoneal exudate cells (PECs) 48 hrs after administration of 10 microg and 100 microg ip HBP demonstrated a 1.7-fold increase in the total number of macrophages compared with carrier control (p < .05). PHAGOCYTOSIS: A flow cytometric in vitro assay demonstrated that administration of 10 microg ip HBP alone did not enhance phagocytosis of fluorescent Escherichia coli in PECs. However, 24-hr pretreatment with 10 microg of HBP followed by CLP increased phagocytosis in PECs 1.8-fold compared with the control CLP group (p = .04). RECEPTOR EXPRESSION: CD16/CD32w expression in PECs did not change after HBP or CLP. CD11b and CD18 expression in PECs was increased significantly after CLP compared with PECs from non-CLP-challenged animals (p < .05). Pretreatment with 10 microg of HBP did not further enhance CD11b/CD18 expression in PECs. Recombinant HBP increases survival in murine fecal peritonitis. The mechanisms by which HBP reduces septic death are not fully understood, but they include monocyte chemotaxis and increased phagocytosis of E. coli by PECs. Our data suggest that the inflammatory response induced by CLP is important for the effect of HBP to enhance phagocytosis.