title: Ligand-dependent regulation of T cell development and activation.
abstract: Mature CD4+ and CD8 + T lymphocytes develop in the thymus from precursors with diverse clonally distributed receptors, possessing binding sites with negligible, intermediate, or high affinity for selfpeptide major histocompatibility complex (MHC) ligands. Positive- and negative-selection processes acting on this precursor pool yield a peripheral T cell population comprised of cells with receptors (TCR) capable of self-peptide MHC ligand recognition, but largely depleted of those able to mediate overt self-responsiveness. The Lymphocyte Biology Section of the Laboratory of Immunology studies how self-ligand recognition guides T cell development in the thymus and influences the functionality of naive and activated T cells in the periphery. It also seeks to define the molecular basis for the discrimination between self-ligands and foreign antigens that controls T cell activation to effector function. Finally, it uses a combination of conventional cellular immunological methods, biochemical and biophysical studies, and advanced imaging techniques to visualize, quantitate, and model the various steps in the development of primary and memory T cell immune responses.
authors.affiliation: Lymphocyte Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1892, USA. rgermain@nih.gov
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Germain
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000254:growth & development
chemical_list: D008024:Ligands