title: PD-1 and its ligands in T-cell immunity.
abstract: The past year has seen significant advances in our understanding of the critical roles of negative immunoregulatory signals delivered by the programmed death 1 (PD-1)-PD-1 ligand (PD-L) pathway in regulating T-cell activation and tolerance. Emerging evidence indicates that PD-Ls play an essential role on dendritic cells (DCs), both directly during DC-T cell interactions and indirectly through signaling into the DC. Recent studies point to a novel role for PD-L1 in maintaining tissue tolerance. Finally, PD-1 has recently been shown to be highly expressed on exhausted T cells during chronic viral infection, and blockade of PD-1 or PD-L1 can revive exhausted T cells, enabling them to proliferate and produce effector cytokines.
authors: Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA.
authors: Mary E
authors: ME
authors: Keir
authors: Loise M
authors: LM
authors: Francisco
authors: Arlene H
authors: AH
authors: Sharpe
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology* / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins / Q000276:immunology* / Q000378:metabolism; D060890:B7-H1 Antigen; D002450:Cell Communication / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D008213:Lymphocyte Activation / Q000276:immunology; D061026:Programmed Cell Death 1 Receptor; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; D060890:B7-H1 Antigen; C423236:CD274 protein, human; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor