title: Characterization of the Specificity, Functionality, and Durability of Host T-Cell Responses Against the Full-Length Hepatitis E Virus.
abstract: The interplay between host antiviral immunity and immunopathology during hepatitis E virus (HEV) infection determines important clinical outcomes. We characterized the specificity, functionality, and durability of host T-cell responses against the full-length HEV virus and assessed a novel "Quantiferon" assay for the rapid diagnosis of HEV infection. Eighty-nine volunteers were recruited from Oxford, Truro (UK), and Toulouse (France), including 44 immune-competent patients with acute HEV infection, 18 HEV-exposed immunosuppressed organ-transplant recipients (8 with chronic HEV), and 27 healthy volunteers. A genotype 3a peptide library (616 overlapping peptides spanning open reading frames [ORFs] 1-3) was used in interferon-gamma (IFN-γ) T-cell ELISpot assays. CD4+/CD8+T-cell subsets and polyfunctionality were defined using ICCS and SPICE analysis. Quantification of IFN-γ used whole-blood stimulation with recombinant HEV-capsid protein in the QuantiFERON kit. HEV-specific T-cell responses were detected in 41/44 immune-competent HEV exposed volunteers (median magnitude: 397 spot-forming units/106peripheral blood mononuclear cells), most frequently targeting ORF2. High-magnitude, polyfunctional CD4 and CD8+T cells were detected during acute disease and maintained to 12 years, but these declined over time, with CD8+responses becoming more monofunctional. Low-level responses were detectable in immunosuppressed patients. Twenty-three novel HEV CD4+and CD8+T-cell targets were mapped predominantly to conserved genomic regions. QuantiFERON testing demonstrated an inverse correlation between IFN-γ production and the time from clinical presentation, providing 100% specificity, and 71% sensitivity (area under the receiver operator characteristic curve of 0.86) for HEV exposure at 0.3 IU/mL.
  
  
  
  Robust HEV-specific T-cell responses generated during acute disease predominantly target ORF2, but decline in magnitude and polyfunctionality over time. Defining HEV T-cell targets will be important for the investigation of HEV-associated autoimmune disease. (Hepatology 2016;64:1934-1950).
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
authors.forename: Anthony
authors.initials: A
authors.lastname: Brown
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.|The Royal Melbourne Hospital, Melbourne, Victoria, Australia.
authors.forename: John S
authors.initials: JS
authors.lastname: Halliday
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
authors.forename: Leo
authors.initials: L
authors.lastname: Swadling
authors.affiliation: The Royal Cornwall Hospital, Truro, United Kingdom.
authors.forename: Richie G
authors.initials: RG
authors.lastname: Madden
authors.affiliation: The Royal Cornwall Hospital, Truro, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Bendall
authors.affiliation: The Royal Cornwall Hospital, Truro, United Kingdom.
authors.forename: Jeremy G
authors.initials: JG
authors.lastname: Hunter
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Maggs
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.|Centre for Immunity, Infection and Evolution, University of Edinburgh, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Simmonds
authors.affiliation: Centre for Immunity, Infection and Evolution, University of Edinburgh, United Kingdom.
authors.forename: Donald B
authors.initials: DB
authors.lastname: Smith
authors.affiliation: The Royal Cornwall Hospital, Truro, United Kingdom.
authors.forename: Louisa
authors.initials: L
authors.lastname: Vine
authors.affiliation: The Royal Cornwall Hospital, Truro, United Kingdom.
authors.forename: Cara
authors.initials: C
authors.lastname: McLaughlin
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Collier
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Bonsall
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
authors.forename: Katie
authors.initials: K
authors.lastname: Jeffery
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.|Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, United Kingdom.
authors.forename: Susanna
authors.initials: S
authors.lastname: Dunachie
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.|Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.|National Institute for Health Research (NIHR), Oxford Biomedical Research Centre, Oxford, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Klenerman
authors.affiliation: The Rangueil Hospital, Toulouse, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Izopet
authors.affiliation: The Rangueil Hospital, Toulouse, France.
authors.forename: Nassim
authors.initials: N
authors.lastname: Kamar
authors.affiliation: The Royal Cornwall Hospital, Truro, United Kingdom.
authors.forename: Harry R
authors.initials: HR
authors.lastname: Dalton
authors.affiliation: Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.|Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.|National Institute for Health Research (NIHR), Oxford Biomedical Research Centre, Oxford, United Kingdom.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Barnes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D016751:Hepatitis E / Q000097:blood / Q000175:diagnosis / Q000276:immunology* / Q000821:virology*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D008297:Male; D008875:Middle Aged; D037182:T-Cell Antigen Receptor Specificity; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D007371:Interferon-gamma