title: Decrease in hepatic CD56(+) T cells and V alpha 24(+) natural killer T cells in chronic hepatitis C viral infection.
abstract: OBJECTIVE
  The intrahepatic immune system is likely to play a key role in determining the outcome of hepatitis C virus (HCV) infection. The hepatic lymphocyte repertoire is characterised by high CD8/CD4 T cell ratios and large numbers of gamma delta T cells, natural killer (NK) cells, NK T cells and NK receptor-positive T cells. It is not known which of these populations contribute to immunity against HCV or immune pathology.
  
  
  METHODS
  To explore the relative contributions of lymphocyte subpopulations, we have compared the intrahepatic lymphocyte repertoires and cytokine expression in 13 patients with mild chronic hepatitis C infection, 14 with end-stage hepatitis C cirrhosis and five histologically normal livers by flow cytometry and immunohistochemistry.
  
  
  RESULTS
  CD4(+) T cells bearing alpha beta T cell receptors (TCR) were significantly expanded in livers with chronic HCV infection while CD56(+) alpha beta T cells and V alpha 24 TCR-positive T cells were significantly depleted. Expanded CD4(+)T cells were predominantly Th1 cells, producing interferon-gamma but not interleukin-4.
  
  
  CONCLUSIONS
  Failure to resolve HCV infection may be due to deficient innate and/or memory immune responses, while Th1 cells may mediate immune pathology.
authors.affiliation: Education and Research Centre, St. Vincent's University Hospital, Elm Park, Dublin 4, Ireland.
authors.forename: Tina
authors.initials: T
authors.lastname: Deignan
authors.forename: Michael P
authors.initials: MP
authors.lastname: Curry
authors.forename: Derek G
authors.initials: DG
authors.lastname: Doherty
authors.forename: Lucy
authors.initials: L
authors.lastname: Golden-Mason
authors.forename: Yuri
authors.initials: Y
authors.lastname: Volkov
authors.forename: Suzanne
authors.initials: S
authors.lastname: Norris
authors.forename: Niamh
authors.initials: N
authors.lastname: Nolan
authors.forename: Oscar
authors.initials: O
authors.lastname: Traynor
authors.forename: Gerry
authors.initials: G
authors.lastname: McEntee
authors.forename: John E
authors.initials: JE
authors.lastname: Hegarty
authors.forename: Cliona
authors.initials: C
authors.lastname: O'Farrelly
mesh_terms: D000328:Adult; D000368:Aged; D019002:CD56 Antigen / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000166:cytology*; D005260:Female; D005434:Flow Cytometry; D019698:Hepatitis C, Chronic / Q000276:immunology* / Q000473:pathology*; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry / Q000166:cytology*; D008099:Liver / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D018417:Th1 Cells / Q000737:chemistry / Q000166:cytology*
chemical_list: D019002:CD56 Antigen; D016693:Receptors, Antigen, T-Cell, alpha-beta