• Ph.D., University of Maryland, 1992

Research Interests: Immunological memory or the ability of the immune system to respond with enhanced vigor to pathogens/antigens encountered in the past is a central concept in immunology. This exaggerated recall immune response is the basis of vaccination against infectious diseases. The existence of immunological memory has been recognized for over 2000 years, yet our understanding of this phenomenon is limited, primarily because memory lymphocytes cannot be unequivocally indentified as they lack specific, permanent markers. A novel genetically engineered mouse model system in which memory T cells and their immediate precursors are irreversibly marked will be used to answer fundamental questions in CD8 and CD4 T cell memory. CD8 T cell memory is a crucial arm of the immune system because CD8+ cytotoxic T cells are critical in controlling parasitic, intracellular bacterial and viral infections. CD4 T cells play a central role in modulation immunity by providing help for the clonal expansion and affinity-maturation of antigen-specific B cells and cytotoxic CD8 T cells. In addition, CD4 T cells can act as cytotoxic effectors themselves. Using the mouse model for marking memory T cells we shall:- establish where CD8 and CD4 memory T cells are generated- characterize the cell-cell interactions and clonal dynamics that occur during the course of a viral response- identify when the commitment of activated CD8 T cells to become memory CD8 T cells occursWe have also developed a novel transgenic mouse model system to mark and track memory B-lymphocytes. Together our studies will lay the foundation for a better understanding of the mechanisms involved in memory B and T cell development. The characterization of these processes will provide key information for designing efficient vaccines that provide long-term protective immunity.