Combined treatment with a CXCL12 analogue and antibiotics improves survival and neutrophil recruitment and function in murine sepsis.

Previous studies demonstrated that the CXCL12 peptide analogue CTCE- 0214 (CTCE) has beneficial effects in experimental sepsis induced by caecal ligation and puncture (CLP). We examined the hypothesis that CTCE recruits neutrophils (polymorphonuclear leucocytes; PMN) to the site of infection, enhances PMN function and improves survival of mice in CLPinduced sepsis with antibiotic treatment. Mice with sepsis (n = 15) were administered imipenem (25 mg/kg) and CTCE (10 mg/kg) subcutaneously versus vehicle control at designated intervals post-CLP. CTCE treatment increased PMN recruitment in CLP-induced sepsis, as evidenced by increased PMN in blood, by 2.4 ± 0.6 fold at 18 hr, 2.9 ± 0.6 fold at 24 hr, and in peritoneal fluid by 2.0 ± 0.2 fold at 24 hr versus vehicle control. CTCE treatment reduced bacterial invasion in blood [colonyforming units (CFU) decreased 77 ± 11%], peritoneal fluid (CFU decreased 78 ± 9%) and lung (CFU decreased 79 ± 8% versus CLP vehicle). The improved PMN recruitment and bacterial clearance correlated with reduced mortality with CTCE treatment (20% versus 67% vehicle controls). In vitro studies support the notion that CTCE augments PMN function by enhancing phagocytic activity (1.25 ± 0.02 fold), increasing intracellular production of reactive oxygen species (32 ± 4%) and improving bacterial killing (CFU decreased 27 ± 3%). These composite findings support the hypothesis that specific CXCL12 analogues with ancillary antibiotic treatment are beneficial in experimental sepsis, in part, by augmenting PMN recruitment and function. [ABSTRACT FROM AUTHOR]