Dr. Marks' research is focused on understanding the role of the vasculature in mediating inflammation, and in causing tissue injury in autoimmune diseases. He is exploiting viruses that exhibit vascular tropism to identify novel molecules expressed by vascular endothelial cells. Dengue virus causes a febrile illness in humans that is associated with considerable vascular pathology. Dr. Marks hypothesized that identification of the target cell receptor used by dengue virus could lead to identification of novel vascular endothelial cell receptors. He identified the dengue receptor on some cells as a novel highly sulfated form heparan sulfate glycosaminoglycan. However, the endothelial cell receptor is a distinct structure, an o-linked mucinous glycoprotein. He also identified 3 distinct glycan-binding motifs in the dengue virus envelope protein, and considerable evidence indicates that these regions account for target cell binding activity. Compounds have been identified that inhibit dengue virus infection of target cells. Dr. Marks is now pursuing this project both as a broad investigation into dengue virus pathobiology, as well as attempting to fully characterize and identify the vascular endothelial cell receptor for dengue virus.