title: The B7/CD28 costimulatory family in autoimmunity.
abstract: Host defense is dependent on the appropriate induction of immune responses. A central concept in immunology is the ability of the immune system to differentiate foreign from self-antigens. The failure of the immune response to recognize foreign pathogens can result in infection and disease in the host. The inappropriate response of the immune system to self-antigens is equally problematic, leading to autoimmune disease. Central and peripheral tolerance mechanisms control self-reactive T-cell responses and protect peripheral tissues from autoimmune attack. This review examines the roles of B7/CD28 family members, which can augment or antagonize T-cell receptor signaling, in the regulation of central and peripheral T-cell tolerance. We also discuss how B7/CD28 pathways influence both T-cell-intrinsic and -extrinsic mechanisms of regulation.
authors.affiliation: Department of Pathology, Harvard Medical School, Brigham and Women's Hospital, Boston, MA 02115-5727, USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Keir
authors.forename: Arlene H
authors.initials: AH
authors.lastname: Sharpe
mesh_terms: D000818:Animals; D015551:Autoimmunity / Q000235:genetics / Q000276:immunology*; D018122:B7-1 Antigen / Q000235:genetics / Q000276:immunology*; D018106:CD28 Antigens / Q000235:genetics / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D007108:Immune Tolerance / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
chemical_list: D018122:B7-1 Antigen; D018106:CD28 Antigens