Effect of neutrophils from septic patients on endothelial barrier function

Abstract

BACKGROUNDSepsis is marked by systemic activation of the inflammatory system. With ongoing inflammation, integrity of the endothelium is compromised, leading to vascular leak, hypotension, and organ hypoperfusion. The effect of neutrophils obtained from septic patients on the integrity of the endothelial monolayer was examined and compared to naïve and fMLP‐activated cells.METHODSBlood was obtained from septic patients and healthy volunteers. Neutrophils were purified from whole blood using anti‐CD15 affinity bead purification. Human umbilical vein endothelial cells were grown to confluence and activated with TNFα. The relative effect of neutrophils on endothelial barrier function was determined by endothelial cell‐substrate impedance sensing.RESULTSAll neutrophil populations decreased monolayer resistance; however, the kinetics and extent of effect varied according to cell source and treatment. Neutrophils from septic patients caused less decrease in barrier function and exhibited a more biphasic response over time, compared to naïve and activated neutrophils.CONCLUSIONSNeutrophils from septic patients manifest a distinctly different effect on endothelial barrier function when compared to fully activated or naïve cells. Supported by NIHGM066194.