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6th World Congress on Inflammation August 2-6, 2003 Vancouver, Canada

Abstract

Glucan Protects the Integrity of an Endothelial Monolayer in the Presence of Activated Neutrophils.

Vassiliki Tsikitis, Nicole Morin, Elizabeth Harrington, Jonathan Reichner. Rhode Island Hospital Dept. of Surgery, Brown University Medical School,
Providence, R.I

Beta glucan

CR3 (CD11b/CD18) is unique among the leukocyte beta2 integrins because, apart from the ligand-binding I-domain, it contains a lectin-like domain.

Glucans are beta (1-3)-linked glucose polymers, which can bind to the CR3 lectin-like domain. Co-occupancy of the lectin-like domain with beta-glucan and the I-domain with fibronectin promotes neutrophil (PMN) chemotaxis.

The current study was undertaken to determine whether treatment of activated neutrophils with beta-glucan would alter PMN:endothelial cell interactions by a CR3-dependent mechanism. Electric Cell Substrate Impedance Sensing (ECIS) was used to evaluate the barrier function of an intact pulmonary capillary endothelial monolayer. Human PMNs were activated, or not, with formyl-met-leu-phe (fMLP), added to a confluent endothelial monolayer and barrier function was measured over time. Although activated PMNs induced a 60±5% (SEM) decrease in normalized monolayer resistance, addition of beta-glucan maintained optimal barrier function. Therefore, beta-glucan may protect endothelial barrier function in the presence of activated PMNs concerning inflammation.