title: Hepatitis C virus-specific cellular immune responses in individuals with no evidence of infection.
abstract: The detection of hepatitis C virus (HCV)-specific T cell responses in HCV-uninfected, presumably unexposed, subjects could be due to an underestimation of the frequency of spontaneously resolving infections, as most acute HCV infections are clinically silent. To address this hypothesis, HCV-specific cellular immune responses were characterized, in individuals negative for an HCV PCR assay and humoral response, with (n = 32) or without (n = 33) risk of exposure to HCV. Uninfected volunteers (n = 20) with a chronically HCV-infected partner were included as positive controls for potential exposure to HCV and HCV infection, respectively. HCV-specific T cell responses in freshly isolated peripheral blood mononuclear cells were studied ex vivo by ELISPOT and CFSE-based proliferation assays using panels of HCV Core and NS3-derived peptides. A pool of unrelated peptides was used as a negative control, and a peptide mix of human cytomegalovirus, Epstein-Bar virus and Influenza virus as a positive control. Overall, 20% of presumably HCV-uninfected subject tested had detectable T-cell responses to the virus, a rate much higher than previous estimates of HCV prevalence in developed countries. This result would be consistent with unapparent primary HCV infections that either cleared spontaneously or remained undetected by conventional serological assays.
authors.affiliation: Laboratoire d'Immunopathologie Virale, Institut Pasteur; and CNRS URA 3015, 25 rue du Dr Roux, 75015 Paris, France. yves.riviere@pasteur.fr
authors.forename: Yves
authors.initials: Y
authors.lastname: Rivière
authors.forename: Thomas
authors.initials: T
authors.lastname: Montange
authors.forename: Geneviève
authors.initials: G
authors.lastname: Janvier
authors.forename: Caroline
authors.initials: C
authors.lastname: Marnata
authors.forename: Ludovic
authors.initials: L
authors.lastname: Durrieu
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Chaix
authors.forename: Maria
authors.initials: M
authors.lastname: Isaguliants
authors.forename: Odile
authors.initials: O
authors.lastname: Launay
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bresson
authors.forename: Stanislas
authors.initials: S
authors.lastname: Pol
mesh_terms: D000956:Antigens, Viral / Q000276:immunology*; D049109:Cell Proliferation; D058501:Enzyme-Linked Immunospot Assay; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D006805:Human Experimentation; D006801:Humans; D007111:Immunity, Cellular; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D015995:Prevalence
chemical_list: D000956:Antigens, Viral