The role of hepatitis B virus-specific memory CD8 T cells in the control of viral replication.
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.
Sobao
Yuji
Y
Division of Viral Immunology, Center for AIDS Research, School of Medicine, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
Tomiyama
Hiroko
H
Sugi
Kazuhiro
K
Tokunaga
Michiyo
M
Ueno
Takamasa
T
Saito
Satoru
S
Fujiyama
Shigetoshi
S
Morimoto
Manabu
M
Tanaka
Katsuaki
K
Takiguchi
Masafumi
M
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
D015234:HLA-A Antigens; D010446:Peptide Fragments