Schistosoma mansoni: In VitroAdhesion of Parasite Eggs to the Vascular Endothelium. Subsequent Inhibition by a Monoclonal Antibody Directed to a Carbohydrate Epitope

Lejoly-Boisseau, H., Appriou, M., Seigneur, M., Pruvost, A., Tribouley-Duret, J., and Tribouley, J. 1999.Schistosoma mansoni: In vitroadhesion of parasite eggs to the vascular endothelium. Subsequent inhibition by a monoclonal antibody directed to a carbohydrate epitope.Experimental Parasitology91,20–29.Schistosoma mansonieggs come into direct contact with the vascular endothelium, particularly in the postcapillary venules of the mesenteric tract (oviposition site). We investigated the adhesion of eggs to endothelial cells in a staticin vitroassay and in a flow-basedin vitroassay. LiveS. mansonieggs rapidly attached, in a time-dependent manner, to the human endothelial cell line ECV 304, but not KOH-treated eggs. Activation of ECV monolayers with interleukin-1 promoted liveS. mansonieggs adhesion. Anin vitroflow-based assay of human umbilical vein endothelial cells (HUVEC) showed the influence of wall shear stresses on the attachment of eggs to endothelial cells, particularly under postcapillary venule shear stress conditions. Interleukin-1 activation of HUVEC promoted adhesion between live eggs and endothelial cells. Higher wall shear stresses were needed to obtain the detachment of eggs from activated endothelial cells than control cells. Preincubation of interleukin-1-activated HUVEC, in a staticin vitroassay, with monoclonal antibodies specific for intercellular adhesion molecule-1, E-selectin, and vascular cell adhesion molecule-1 significantly decreased adhesion of live eggs. Previous studies have shown that a monoclonal antibody specific for a schistosome carbohydrate epitope abundant in eggs is related to the Lewis X antigen. In this study, the anti-Lewis X-specific monoclonal antibody was used for adhesion-inhibition assays. Preincubation of eggs with this monoclonal antibody significantly decreased adhesion of live eggs to interleukin-1-activated HUVEC culturedin vitro.These results suggest that surface adhesion molecules, expressed by endothelial cells under conditions of interleukin-1 activation, directly participate in egg adhesion and that egg carbohydrate antigens play an important role in liveS. mansoniegg adhesion to the vascular endothelium.