Research in my laboratory is focused on cutaneous and visceral leishmaniases, human parasitic diseases transmitted by infected sand flies. Using mouse and hamster as models, we want to examine 1) the differential responses of target cells (macrophages and dendritic cells) to parasite infection; 2) the impact of dendritic cell-parasite interaction on T cell activation; 3) the role of T helper subsets and their produced cytokines/chemokines in the control of infection and disease pathogenesis; and 4) the factors of parasite or vector origins that may influence the outcome of infection. Given that Leishmania parasites have a complex life cycle and relative large genome size, our research effort has also been directed at identifying parasite antigens using functionally defined CD4+ T cell lines or specific monoclonal antibodies. The biological role of parasite genes/proteins is being tested via DNA immunization. Our long-term goal is to understand at the molecular level pathogenic and protective mechanisms operating on both sides of the host-parasite interactions.