Our Parasitology program includes a multidisciplinary malaria program studying the molecular and immunological mechanisms involved in the induced protective T cell responses against Plasmodium-infected hepatocytes (Drs. Azad and Sacci), vaccine development and testing (Drs. Levine and Sztein), and molecular epidemiology (Dr. Plowe).
Because gene expression during the liver stage of parasite development remains incompletely understood, ongoing projects have been aimed at identifying stage-specific gene expression, through molecular approaches, and defining what role these gene products have in the biology of the parasite. Detailed studies are also underway to assess the role of specific antigens in protective immunity induced by irradiated sporozoites in the Plasmodium yoelii mouse model. A novel mouse model of P. falciparum infection utilizing chimeric human livers has recently been developed by Dr. Sacci.
The Center for Vaccine Development group (Drs. Levine, Sztein and Plowe) has been studying sporozoite and blood-stage antigens as potential components of a malaria subunit vaccine using a Salmonella-delivery system and other approaches. Dr. Plowe also conducts laboratory and field research on the molecular mechanisms and molecular epidemiology of resistance to antimalarial drugs, particularly the antifolate drugs and chloroquine.
Our Parasitology program also includes vector biology and pathogenesis of vector borne pathogens. Over the past twenty years, we have seen worldwide emergence and resurgence of arthropod-borne pathogens such as West Nile, Lyme borreliosis, malaria, anaplasmoses, ehrlichioses, and typhus. The arthropod stage of pathogenic bacteria and protozoan parasites of human and domestic animals is a critical period where marked changes occur that will influence the transmission to and infectivity for the mammalian host. Dr. Azad is deciphering the molecular events underlying rickettsial activation within the tick vector where transmission would not occur unless a sustained rise in temperature resulted in the upregulation of virulence elements.
Expertise in the genomics of parasites and insect vectors of infectious agents has recently been added with the establishment of the Institute for Genome Sciences. The research of Dr. Carneiro da Silva centers on the evolutionary forces and genetic processes that shape genome evolution, including mutation rates and transposable elements, with a particular emphasis on parasites in the phylum Apicomplexa.
At the Columbus Center, Drs. Fernandez-Robledo and Vasta are engaged in the genomics, diagnostics, and host – parasite interactions of Perkinsus marinus, a protozoan parasite that has devastated the eastern oyster in the Chesapeake Bay. Dr. Fernandez-Robledo has developed a transfection system for P. marinus that allows heterologous gene expression and protein production of genes and proteins from other Apicomplexa parasites. Dr. Vasta has investigated the innate immune system of oysters with a recent emphasis on the role of a unique host galectin (CvGal) that serves as a receptor for entry of P. marinus trophozoites.