title: Analysis of successful immune responses in persons infected with hepatitis C virus.
abstract: Although hepatitis C virus (HCV) infection is very common, identification of patients during acute infection is rare. Consequently, little is known about the immune response during this critical stage of the disease. We analyzed the T lymphocyte response during and after acute resolving HCV infection in three persons, using interferon (IFN)-gamma enzyme-linked immunospot (ELISPOT) and human histocompatibility leukocyte antigen (HLA) peptide tetramer assays. Acute infection was associated with a broadly directed T helper and cytotoxic T lymphocyte (CTL) response, which persisted after resolution of clinical hepatitis and clearance of viremia. At the earliest time point studied, highly activated CTL populations were observed that temporarily failed to secrete IFN-gamma, a "stunned" phenotype, from which they recovered as viremia declined. In long-term HCV-seropositive persons, CTL responses were more common in persons who had cleared viremia compared with those with persistent viremia, although the frequencies of HCV-specific CTLs were lower than those found in persons during and after resolution of acute HCV infection. These studies demonstrate a strong and persistent CTL response in resolving acute HCV infection, and provide rationale to explore immune augmentation as a therapeutic intervention in chronic HCV infection.
authors.affiliation: Nuffield Department of Clinical Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United Kingdom.
authors.forename: F
authors.initials: F
authors.lastname: Lechner
authors.forename: D K
authors.initials: DK
authors.lastname: Wong
authors.forename: P R
authors.initials: PR
authors.lastname: Dunbar
authors.forename: R
authors.initials: R
authors.lastname: Chapman
authors.forename: R T
authors.initials: RT
authors.lastname: Chung
authors.forename: P
authors.initials: P
authors.lastname: Dohrenwend
authors.forename: G
authors.initials: G
authors.lastname: Robbins
authors.forename: R
authors.initials: R
authors.lastname: Phillips
authors.forename: P
authors.initials: P
authors.lastname: Klenerman
authors.forename: B D
authors.initials: BD
authors.lastname: Walker
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D005260:Female; D006526:Hepatitis C / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000097:blood; D018936:Hepatitis C Antigens / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000939:Epitopes; D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D009842:Oligopeptides; D007371:Interferon-gamma