Our research focuses primarily on the molecular pathogenesis of parasitic helminth infections in children. The majority of this work involves laboratory investigations on the pathogenesis of hookworm infection, a leading cause of anemia and malnutrition in developing countries. Using in vitro and in vivo studies, we seek to characterize the molecular mechanisms through which adult hookworms, bloodfeeding nematode parasites, evade host defenses in order to feed successfully while attached to the intestinal mucosa. Novel hookworm proteins secreted at the site of attachment have been identified, including anticoagulants, platelet inhibitors, immunomodulatory compounds, and tissue degrading proteases. Using an animal model of Ancylostoma ceylanicum infection, we have also characterized humoral and cellular immune responses to hookworm challenge, and demonstrated that immunization with recombinant hookworm antigens confers partial protection against disease in vivo. A second focus of our laboratory research is the characterization of anti-thrombotics from a variety of hematophagous invertebrates. These collaborative studies have led to the isolation of novel compounds from the tsetse fly Glossina morsitans, the blood fluke Schistosoma mansoni, and the tick Ixodes scapularis. Ultimately, these potent anti-thrombotics represent viable molecular targets for strategies aimed at preventing the diseases caused or transmitted hematophagous invertebrates. Because of their unique mechanisms of action, these compounds may also have therapeutic potential for the treatment of numerous conditions associated with thrombosis, including heart disease, stroke, and cancer.