AIM: To determine whether dendritic cells (DCs) fromchronic hepatitis B patients could induce HBV antigen-specific T cell responses or not.METHODS: DCs were generated from peripheral bloodmononudear ceils of patients with chronic hepatitis B (CHB)infection and healthy donors.We compared the phenotypesof these Des and their ability to secrete cytokines and toparticipate in mixed lymphocyte reactions.In addition,autologous lymphocytes were cultured with DCs loaded withHBV core region peptide HBcAg8-27,an epitope recognizedby cytotoxic T lymphocytes (CTL),and bearing human leucocyteantigen (HLA)-A2 for 10 d.Cytokine secretion and lytic activityagainst peptide-pulsed target cells were assessed.RESULTS: DCs with typical morphology were generatedsuccessfully by culturing peripheral blood mononuclear cells(PBMCs) from CHB patients with AIM-V containing GM-CSFand IL-4.Compared with DCs from normal donors,thelevel of CD80 expressed in DCs from CHB patients waslower,and Des from patients had lower capacity ofstimulate T cell proliferation.When PBMCs isolated frompatients with chronic or acute hepatitis B infection and fromnormal donors were cocultured with HBcAg18-27 peptide,the antigen-specific memory response of PBICs from acutehepatitis B patients was stronger than that of PBMCs fromchronic hepatitis B patients or normal donors.PBMCscocultured with DCs treated with HBcAg18-27 CTL epitopepeptide induced an antigen-specific T cell reaction,in whichthe level of secreted cytokines and lyric activity were higherthan those produced by memory T cells.CONCLUSION: DCs from patients with CHB can induceHBV antigen-specific T cell reactions,including secretionof cytokines essential for HBV clearance and for killing cellsinfected with HBV. AIM: To determine whether dendritic cells (DCs) from chronic hepatitis B patients may induce HBV antigen-specific T cell responses or not. METHODS: DCs were generated from peripheral blood mononudear ceils of patients with chronic hepatitis B (CHB) infection and healthy donors. compared the phenotypes of these Des and their ability to secrete cytokines and toparticipate in mixed lymphocyte reactions. In addition, autologous lymphocytes were cultured with DCs loaded with HBV core region peptide HBcAg8-27, an epitope recognized by cytotoxic T lymphocytes (CTL), and bearing human leukocyte antigen (HLA) -A2 for 10 d. Cytokine secretion and lytic activity of peptide-pulsed target cells were assessed .RESULTS: DCs with typical morphology were generated successfully by culturing peripheral blood mononuclear cells (PBMCs) from CHB patients with AIM-V containing GM-CSF and IL-4.Compared with DCs from normal donors, the level of CD80 expressed in DCs from CHB patients was lower, and Des from patients had low er capacity ofstimulate T cell proliferation. Whites PBMCs isolated from patients with chronic or acute hepatitis B infection and from normal donors were cocultured with HBcAg18-27 peptide, the antigen-specific memory response of PBICs from acute hepatitis B patients was stronger than that of PBMCs from chronic hepatitis B patients or normal donors. PBMCscocultured with DCs treated with HBcAg18-27 CTL epitope peptide induced an antigen-specific T cell reaction, in which the level of secreted cytokines and lyric activity were higherthan those produced by memory T cells. CONCLUSION: DCs from patients with CHB can induceHBV antigen-specific T cell reactions, including secretionof cytokines essential for HBV clearance and for killing cells infected with HBV.