title: PD-1 expression in acute hepatitis C virus (HCV) infection is associated with HCV-specific CD8 exhaustion.
abstract: Hepatitis C virus (HCV)-specific CD8 cell exhaustion may represent a mechanism of HCV persistence. The inhibitory receptor PD-1 has been reported to be up-regulated in exhausted CD8 cells. Therefore, we studied PD-1 expression longitudinally during acute HCV infection. Most HCV-specific CD8 cells expressed PD-1 at the time of acute illness, irrespective of the final outcome. PD-1 expression declined with the acquisition of a memory phenotype and recovery of an efficient CD8 cell function in resolving HCV infections, whereas high levels were maintained when HCV persisted and HCV-specific CD8 cells remained dysfunctional. Blocking PD-1/PDL-1 interaction with an anti-PDL-1 antibody improved the capacity of expansion of virus-specific CD8 cells.
authors.affiliation: Laboratorio Immunopatologia Virale, Unit of Infectious Diseases and Hepatology, Azienda Ospedaliero-Universitaria di Parma, Via Gramsci 14, 43100 Parma, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Urbani
authors.forename: Barbara
authors.initials: B
authors.lastname: Amadei
authors.forename: Daniela
authors.initials: D
authors.lastname: Tola
authors.forename: Marco
authors.initials: M
authors.lastname: Massari
authors.forename: Simona
authors.initials: S
authors.lastname: Schivazappa
authors.forename: Gabriele
authors.initials: G
authors.lastname: Missale
authors.forename: Carlo
authors.initials: C
authors.lastname: Ferrari
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D016174:Hepacivirus / Q000276:immunology*; D006526:Hepatitis C / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D016131:Lymphocyte Subsets; D061026:Programmed Cell Death 1 Receptor
chemical_list: D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor