ENDOTHELIAL-CELL MONOLAYERS AS A MODEL SYSTEM TO INVESTIGATE DENGUE SHOCK SYNDROME

Monolayers of the human endothelial cell line ECV304 were compared wit h those from primary endothelial cells from human umbilical cord veins (HUVEC) for potential use as an assay system to investigate vasoactiv e mediator levels in dengue viral infections. Permeability increases w ere induced in ECV304 monolayers which were more easily reproduced tha n in primary cells. The cell line monolayers were considerably more st able which allowed multiple consecutive assays to be undertaken on the same monolayers. Permeability responsiveness was maximal at 2 and 3 d ays postseeding and declined over a period of 7 days. The cell line fo rmed monolayers which showed time- and concentration-dependent permeab ility increases in response to thrombin, tumour necrosis factor-alpha (TNF-alpha) or interleukin-1 alpha (IL-1 alpha) in a manner similar to primary endothelial cells. Permeability increases induced by TNF-alph a were reversible and increased exposure time required a longer recove ry period. The cell line, like primary endothelial cells, supported de ngue viral replication. Direct infection of confluent monolayers on po lycarbonate membranes was not cytolytic and did not increase the perme ability of the monolayers over a 15-day period. (C) 1998 Elsevier Scie nce B.V. All rights reserved.