Steve Benedict

Biography

T lymphocytes are crucial cells in the immune response, controlling B cell and macrophage function by T helper and T regulatory activity, synthesizing cytokines, and providing cytotoxic activity. Before T cells can function, they must be activated by specific antigen, and the ability to control T cell activation would be of great importance in controlling the immune response to foreign antigens. T cells are activated through two signals, the antigen signal is very specific and without a second signal, causes the T cell to die or become anergic. The second signal can be delivered through any of several proteins located on the T cell surface. This combination of signals, called costimulation, leads to activation of the T cell and in some cases to differentiation of the cell to a more mature phenotype capable of performing new functions. We study how multiple T cell signaling regulates T cell activation, adhesion, migration/homing, differentiation and function, and how the T cell surface molecule ICAM-1 plays a role in these processes. We use mouse models to study thymic differentiation and the role of ICAM-1 in resistance to infectious disease. We study post thymic differentiation of naïve T cells in young and older humans. We study the participation of signaling through ICAM-1 in autoimmune diseases such as rheumatoid arthritis or multiple sclerosis. We are studying aging and immunosenescence during differentiation of human naïve T cells to memory or to regulatory T cells in response to several combinations of signals introduced at the T cell surface. We are studying the immune response in patients who are undergoing total parenteral nutrition.

Research Interest

T cell activation, cell signaling, adhesion molecules.