title: The B7-CD28 superfamily.
abstract: The B7-1/B7-2-CD28/CTLA-4 pathway is crucial in regulating T-cell activation and tolerance. New B7 and CD28 molecules have recently been discovered and new pathways have been delineated that seem to be important for regulating the responses of previously activated T cells. Several B7 homologues are expressed on cells other than professional antigen-presenting cells, indicating new mechanisms for regulating T-cell responses in peripheral tissues. Some B7 homologues have unknown receptors, indicating that other immunoregulatory pathways remain to be described. Here, we summarize our current understanding of the new members of the B7 and CD28 families, and discuss their therapeutic potential.
authors.affiliation: Immunology Research Division, Department of Pathology, Brigham, and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, Massachusetts 02115, USA. asharpe@rics.bwh.harvard.edu
authors.forename: Arlene H
authors.initials: AH
authors.lastname: Sharpe
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Freeman
mesh_terms: D000069594:Abatacept; D000818:Animals; D015703:Antigens, CD / Q000502:physiology; D000943:Antigens, Differentiation / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000737:chemistry / Q000502:physiology; D000954:Antigens, Surface / Q000502:physiology; D051017:Apoptosis Regulatory Proteins; D001327:Autoimmune Diseases / Q000628:therapy; D001402:B-Lymphocytes / Q000276:immunology; D018122:B7-1 Antigen / Q000502:physiology*; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000502:physiology*; D060908:CTLA-4 Antigen; D002450:Cell Communication; D002454:Cell Differentiation; D006801:Humans; D018796:Immunoconjugates; D060889:Inducible T-Cell Co-Stimulator Protein; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000502:physiology; D061026:Programmed Cell Death 1 Receptor; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497964:CD86 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556692:ICOS protein, human; D018796:Immunoconjugates; D060889:Inducible T-Cell Co-Stimulator Protein; D008562:Membrane Glycoproteins; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D000069594:Abatacept