D R Dixon1, L Karimi-Naser, R P Darveau, K P Leung. 1. Microbiology and Immunology Branch, US Army Dental and Trauma Research Detachment, Walter Reed Army Institute of Research, Great Lakes Naval Training Station, Great Lakes, IL, USA. douglas.dixon@na.amedd.army.mil
Abstract
BACKGROUND AND OBJECTIVE: Host responses following the recognition of bacterial lipopolysaccharide can range from acute inflammation to septic shock. The aim of this study was to evaluate the ability of the KSL-W decapeptide to bind to and block the endotoxic effects of lipopolysaccharide. MATERIAL AND METHODS: An enzyme-linked immunosorbent assay-based binding assay using fluorescently labeled KSL-W to detect adsorbed Escherichia coli O55:B5 lipopolysaccharide was employed. A commercially available recombinant Factor C lipopolysaccharide detection assay, hemagglutination of rabbit erythrocytes as well as E-selectin expression in human umbilical vein endothelial cells were used to assess the anti-endotoxic effects after KSL-W exposure to E. coli lipopolysaccharide as well as to oral lipopolysaccharide samples. RESULTS: Lipopolysaccharide-binding assays using E. coli O55:B5 lipopolysaccharide revealed both a higher maximal binding range (532-713 microM) and a half-maximum binding concentration (70-185 microM) for the KSL-W peptide when compared with its analog control. Significant inhibition of E-selectin expression in human umbilical vein endothelial cells (p < 0.0001) as well as hemagglutination of rabbit erythrocytes occurred after the interaction of KSL-W with E. coli lipopolysaccharide. Recombinant Factor C enzyme detection inhibition revealed dose-dependent inhibition values ranging from 1.0-51.8 microM. which were dependent upon the type of lipopolysaccharide sample tested. CONCLUSION: These results demonstrate that for the concentrations tested, the KSL-W decapeptide was nontoxic to mammalian cells and could bind to and block the host recognition and response towards enteric, as well as oral, lipopolysaccharide samples.
BACKGROUND AND OBJECTIVE: Host responses following the recognition of bacterial lipopolysaccharide can range from acute inflammation to septic shock. The aim of this study was to evaluate the ability of the KSL-W decapeptide to bind to and block the endotoxic effects of lipopolysaccharide. MATERIAL AND METHODS: An enzyme-linked immunosorbent assay-based binding assay using fluorescently labeled KSL-W to detect adsorbed Escherichia coli O55:B5 lipopolysaccharide was employed. A commercially available recombinant Factor C lipopolysaccharide detection assay, hemagglutination of rabbit erythrocytes as well as E-selectin expression in human umbilical vein endothelial cells were used to assess the anti-endotoxic effects after KSL-W exposure to E. colilipopolysaccharide as well as to oral lipopolysaccharide samples. RESULTS:Lipopolysaccharide-binding assays using E. coli O55:B5 lipopolysaccharide revealed both a higher maximal binding range (532-713 microM) and a half-maximum binding concentration (70-185 microM) for the KSL-W peptide when compared with its analog control. Significant inhibition of E-selectin expression in human umbilical vein endothelial cells (p < 0.0001) as well as hemagglutination of rabbit erythrocytes occurred after the interaction of KSL-W with E. colilipopolysaccharide. Recombinant Factor C enzyme detection inhibition revealed dose-dependent inhibition values ranging from 1.0-51.8 microM. which were dependent upon the type of lipopolysaccharide sample tested. CONCLUSION: These results demonstrate that for the concentrations tested, the KSL-W decapeptide was nontoxic to mammalian cells and could bind to and block the host recognition and response towards enteric, as well as oral, lipopolysaccharide samples.