Graduate Students and Post Doctoral Fellows in the lab are working on research that is focused on CD8 and CD4 T cell responses to a variety of viral and bacterial infections to help understand the development of immunological protection from re-infection. We observe and manipulate pathogen specific T cell responses over time by using MHC tetramers, adoptive transfer of transgenic T cells, fluorescence flow cytometry and sorting, and gene microarry analysis. Upon activation in lymphoid tissue, rare pathogen-specific naïve T cells proliferate, acquire effector functions, disseminate throughout the organism, and contribute to the eradication of pathogens. In situations where antigen is successfully eliminated, most effector T cells die by apoptosis. However, a fraction of effector T cells escape death and differentiate into long-lived memory T cells that contribute to protective immunity. We are currently dedicated to elucidating the developmental cues that govern T cell migration to different anatomical locations, commitment to the memory lineage, and the contribution of memory T cell differentiation state and location to protection from re-infection. Memory T cells that reside at common portals of pathogen entry or infection, especially the intestinal mucosa, are of particular interest. By understanding these issues, we hope to contribute to the development of better vaccination strategies, and are currently focused on informing development of a protective HIV vaccine.