Professor of Medicine Harvard Medical School

Investigator, Full Prof (M) Center for Immunology and Inflammatory Diseases, Mass General Research Institute

Bob and Laura Reynolds MGH Research Scholar 2014-2019 Mass General Research Institute, Massachusetts General Hospital

antigen-presenting cells; cell communication; cell movement; chemokine; cytotoxic t-lymphoctes; giant cells; hiv; immunotherapy; lymph nodes; lymphocytes; microscopy; microscopy fluorescence; multiphoton; video microscopy

T lymphocytes are part of the adaptive immune system. They are powerful players in the defense against infection and can be effective against tumors, but they are also involved in autoimmune responses, leading to diseases such as diabetes, arthritis, or multiple sclerosis.

T cell responses arise from clonal expansion of a small number of naïve precursors through antigenic priming by dendritic cells in secondary lymphoid organs, such as lymph nodes and the spleen. Once these naïve T cells have differentiated to effector T cells, they migrate to the blood, from where they are recruited to peripheral tissues to combat disease.

To prevent attacks on healthy tissues, the execution of T cell effector functions is tightly linked to the recognition of cognate antigen. In addition, immune responses are regulated through diverse inhibitory and stimulatory signals that T cells encounter in peripheral tissues. Dr. Mempel's lab is seeking to understand how the function of T cells is regulated through their interaction with other cells, structural tissue components and soluble mediators that they encounter in tissues. Their main approach to this end is direct dynamic in vivo visualization of immune processes at cellular and subcellular resolution in living mice, using multiphoton intravital microscopy.