title: The role of hepatitis B virus-specific memory CD8 T cells in the control of viral replication.
abstract: OBJECTIVE
  The aim of this study is to clarify the differences of host immune responses between acute self-limited and chronic persistent hepatitis B virus (HBV) infections by quantitative and qualitative analysis of HLA-A*2402-restricted HBV-specific CD8+ T cells.
  
  
  METHODS
  HBV-specific CD8+ T cells in peripheral blood mononuclear cells (PBMCs) from patients infected with HBV were analyzed by flow cytometry using two HLA-A*2402-HBV peptide tetrameric complexes.
  
  
  RESULTS
  High numbers of HBV-specific CD8+ T cells were detected in acute phase PBMCs from most individuals with acute HBV infection while the number of these cells was greatly reduced in recovery phase PBMCs. HBV-specific CD8+ T cells were not detected in PBMCs from individuals with chronic HBV infection except for one patient during acute exacerbation. HBV-specific CD8+ T cells were induced by in vitro peptide stimulation in PBMCs from chronic HBV carriers with a low level of serum HBV-DNA but not from those with a high level of serum HBV-DNA. CD28CD45RA phenotype analysis showed that HBV-specific CD8+ T cells in acute phase PBMCs predominantly express a memory T cell phenotype.
  
  
  CONCLUSIONS
  HBV-specific memory CD8+ T cells may play a crucial role in complete clearance of HBV from patients with acute HBV hepatitis.
authors.affiliation: Division of Viral Immunology, Center for AIDS Research, School of Medicine, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sobao
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tomiyama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sugi
authors.forename: Michiyo
authors.initials: M
authors.lastname: Tokunaga
authors.forename: Takamasa
authors.initials: T
authors.lastname: Ueno
authors.forename: Satoru
authors.initials: S
authors.lastname: Saito
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Fujiyama
authors.forename: Manabu
authors.initials: M
authors.lastname: Morimoto
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Tanaka
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takiguchi
mesh_terms: D000208:Acute Disease; D044466:Asian People; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D005434:Flow Cytometry; D015234:HLA-A Antigens / Q000276:immunology; D006509:Hepatitis B / Q000276:immunology*; D006515:Hepatitis B virus / Q000254:growth & development / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000821:virology; D014779:Virus Replication / Q000276:immunology
chemical_list: D015234:HLA-A Antigens; D010446:Peptide Fragments