T cell responses in autoimmunity and chronic infections My laboratory studies CD8 and CD4 T cell responses to proteins, which are persistently present in an organism to elucidate how chronic interaction with cognate antigen impacts T cell selection, differentiation and survival. We observe and manipulate chronic pathogen or self-specific T cell responses over time by using MHC tetramers, adoptive transfer of transgenic T cells and fluorescence flow cytometry. We are currently interested in understanding what maintains the population of memory T cells specific for persistent pathogens, such as polyoma virus. In addition, we are interested in elucidating how tolerance is induced and maintained to intestinal protein, as breakdown of this can lead to diseases such as ulcerative colitis and Crohn's disease. By understanding these processes, we can learn how to manipulate the immune system for eradication of persistent infections, as well as interfering with the development and progression of autoimmunity.