Objective To investigate the expression feature of hepatitis B virus(HBV)-specific cytotoxic T lymphocytes(CTL),and analyze the role of CTL in immune response.Methods Peripheral venous blood was collected from 40 acute hepatitis B(AHB) patients hospitalized from Oct.2008 to Jun.2010 in 302 Hospital of PLA for the detection of human leucocyte antigen-A2(HLA-A2).Out of the 40 patients,18 were HLA-A2-positive,and their peripheral blood mononuclear cells were isolated at acute phase and

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... phase if the patients could be contacted.Six HLA-A2-negative AHB patients,18 HLA-A2-positive chronic HB patients and 6 HLA-A2-positive normal persons served as controls.The CTL was stained by fluorescence-labeled anti-CD3 monoclonal antibody,anti-CD8 monoclonal antibody and HBV epitopic pentamers(S183-191,S335-343),and examined with flow cytometry,then analyzed by software Cell-quest.The peak value of alanine aminotransferase(ALT) and HBV load was detected at acute phase of patients,and the correlation was analyzed.Results The average frequencies were 0.23%±0.18% for HBsAg183-191-specific CTL and 0.49%±0.31% for HBsAg335-343-specific CTL at the acute phase of the 18 AHB patients,and they were significantly higher than those in patients with chronic HB,in whom CTL frequencies were 0.07%±0.03% for HBsAg183-191-specific CTL and 0.08%±0.04% for HBsAg335-343-specific CTL(P < 0.01).There was no correlation between the frequency of HBsAg183-191-specific CTL and the peak value of ALT(r=0.4506,P=0.0528),while the frequency of HBsAg335-343-specific CTL was correlated with ALT level(r=0.5642,P=0.0119).Neither the two CTL frequencies showed correlation with virus load.Compared with the acute phase,the CTL frequencies obviously decreased at convalescent phase(P=0.011).Both kinds of CTL were not detectable in HLA-A2-negative AHB patients and HLA-A2-positive healthy individuals.Conclusion HBV-specific CTL may play an important role in both virus clearance and liver impairment.CTL targeting to different HBV epitopes may contribute to the [...]