title: Expression of hepatitis B virus x protein in hepatocytes suppresses CD8 T cell activity.
abstract: BACKGROUND
  CD8(+) T cells contribute to the clearance of Hepatitis B virus (HBV) infection and an insufficient CD8(+) T cell response may be one of the major factors leading to chronic HBV infection. Since the HBx antigen of HBV can up-regulate cellular expression of several immunomodulatory molecules, we hypothesized that HBx expression in hepatocytes might affect CD8(+) T cell activity.
  
  
  METHODS
  We analyzed the activation and apoptosis of CD8(+) T cells co-cultured with primary hepatocytes rendered capable of expressing HBx by recombinant baculovirus infection.
  
  
  RESULTS
  Expression of HBx in hepatocytes induced low production of interferon-γ and apoptosis of CD8(+) T cells, with no effect on CD8 T cell proliferation. However, transcriptional levels of H-2K, ICAM-1 and PD-1 ligand did not correlate with HBx expression in hepatocytes.
  
  
  CONCLUSIONS
  Our results suggest that HBx may inhibit CD8(+) T cell response by regulation of interferon-γ production and apoptosis.
authors.affiliation: Department of Microbiology and Immunology, Ajou University School of Medicine, Suwon 442-721, Korea.
authors.forename: Mi Jin
authors.initials: MJ
authors.lastname: Lee
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Jin
authors.forename: Kyongmin
authors.initials: K
authors.lastname: Kim
authors.forename: Yangkyu
authors.initials: Y
authors.lastname: Choi
authors.forename: Hyoung-Chin
authors.initials: HC
authors.lastname: Kim
authors.forename: Sun
authors.initials: S
authors.lastname: Park