The Role(s) of the Cation Transporter Nramp in the Intracellular Survival of Protistan Parasites

University Of Maryland At Baltimore, Baltimore

Investigators

Abstract

The protozoan parasite Perkinsus marinus causes "Dermo" disease in the eastern oyster, and is responsible for the catastrophic decline of natural and farmed oyster populations. This has resulted in severe damage to the estuarine ecosystem along the Atlantic and Gulf coasts of North America. Because iron is essential for growth, intracellular parasites such as P. marinus must acquire iron from their hosts for successful proliferation. Until recently, however, the mechanisms involved in iron uptake by intracellular parasites have remained obscure. The iron requirement for P. marinus proliferation has been demonstrated and the iron transporter Nramp (Nramp; Natural resistance-associated macrophage protein)cloned from both the parasite (PmNramp) and its oyster host (CvNramp). This has led to the hypothesis that PmNramp represents a mechanism for iron uptake that enables the parasite's successful invasion and proliferation within the oyster host. This project will use molecular, genetic, and biochemical approaches to characterize Nramp in P. marinus to gain insight into its role in virulence, and the impact of competition for iron on the outcome of the parasite/host interaction. it is anticipated that this project will lead to new insights into their role(s) in the virulence of parasites of medical and veterinary relevance. Given the regional relevance of oyster disease, this project is significant in that it will contribute to development of novel intervention strategies to restore natural and farmed oyster populations. From the educational standpoint, the oyster-P. marinus system is well suited for classroom integration of fundamental scientific principles related to host-parasite biology, and this project will involve the participation of undergraduates and high school students and teachers mostly from underrepresented minorities from the Baltimore area, both as interns at the bench and in the classroom, through training programs such as ExPERT (NSF), Chesapeake Teacher Research Fellowship (NOAA), Living Classrooms, Ingenuity, Baltimore Community College, and mentorship programs from Howard, Prince George, and Baltimore Counties.