Effective immunity to pathogens requires that coordinated, multi-cellular responses emerge from a myriad of "conversations" that take place between cells of the innate and adaptive immune compartments. My lab is working to understand the molecular mechanism that mediate the conversations that occur between antigen-presenting cells and T cells that determine if and how a T cell responds to antigen. We are using a variety of classic molecular, cellular, and biochemical techniques, as well as more modern live cell imaging approaches, to probe these processes. We are also developing mouse model systems to determine how individual mechanisms contribute to T cell responses during pathogenic infection or autoimmunity. Altogether, our work is aimed at increasing our basic and practical understanding of T cell activation and regulation.