MMP cellular responses to dengue virus infection-induced vascular leakage.

Dengue hemorrhagic fever and dengue shock syndrome, the major life-threatening outcomes of severe dengue disease, are the consequence of plasma leakage in the vascular areas. We previously demonstrated that dengue virus (DV)-infected dendritic cells (DC) trigger vascular leakage through matrix metalloproteinase (MMP)-9 overproduction, however little is known concerning the consequences of direct infection of macrovascular endothelial cells (MVEC) by DV. In this study, we show that infection of primary human MVEC results in overproduction of MMP-2 and to a lesser extent of MMP-9, leading to enhanced endothelial permeability. This permeability was associated with loss of expression of the vascular endothelium-cadherin cell-cell adhesion. The MMP response to DV infection is strikingly different between DC and MVEC. Therefore, our results demonstrated that endothelial cells are an important target for DV infection, and that DV-induced MMP-2 overproduction by direct infection of endothelial cells may contribute to the pathogenesis of severe dengue infection.