目的 测定慢性乙型肝炎(chb)患者外周血cd4+c25+调节性t细胞(cd4+cd25+treg细胞)的抗原诱导与抑制功能,初步探讨cd4+ cd25+ treg细胞在hbv感染慢性化过程中的作用.方法 采集22例chb患者、11例急性早期乙型肝炎患者(ahb)和20例健康对照者的外周血,分离外周血单核细胞(pbmc)后体外培养,并经重组hbsag或抗人cd3单克隆抗体诱导,流式细胞仪分析诱导前后cd4+ cd25+treg细胞比例的变化.免疫磁珠分选出cd4+ cd25+treg细胞亚群和去除了cd4+ cd25+treg细胞的效应细胞亚群(pbmc-treg),在重组hbsag刺激下进行体外单独培养或共培养,并检测效应细胞的增殖与细胞因子生成量的变化.所有患者均进行hbv血清标记物水平、血清hbv dna载量和肝功能水平的测定.结果 在重组hbsag刺激下,chb组pbmc可诱导出较高比例的cd4+cd25+ treg细胞,且与ahb组、健康对照组之间的差异有统计学意义(f值分别为3.47,4.98,p均＜0.05).体外单独培养时,患者组及健康对照组的cd4+ cd25+ treg细胞的增殖能力较弱,仅能产生微量的ifn-γ和il-10,且组间差异无统计学意义(p＞0.05).ahb组效应细胞的增殖能力和ifn-γ产量均明显高于chb组,而il-10的产量与chb组均较低,组间比较差异无统计学意义(p＞0.05).混合培养时,ahb组及chb组的cd4+ cd25+treg细胞均能显著抑制效应细胞的增殖及ifn-γ的产量(f值分别为4.66,5.24,p均＜0.01).结论 chb患者的外周血cd4+ cd25+ treg细胞可被hbsag特异性诱导,cd4+ cd25+ treg细胞在体外可显著抑制效应细胞的增殖与ifn-γ的分泌,提不cd4+ cd25+treg细胞可能通过抑制抗原特异性t细胞的应答而导致外周免疫耐受,并与hbv感染的慢性化密切相关.; abstract：; objective to investigate the induction and function of circulating cd4+ cd25+ regulatory t cells(cd4+cd25+ treg cells)in patients with chronic hepatitis b,and their role in the progress of chronic hbv infection.methods twenty two patients with chronic hepatitis b(chb),11 patients with acute hepatitis b(ahb)and 20 healthy blood donators were enrolled in the study.after stimulating with recombinant hbv antigen or anti-cd3 mab,the fraction of cd4+ cd25+treg cells in peripheral blood mononuclear cells(pbmc)from different subjects was analyzed using flow cytometry.cd4+cd25+ treg cells and effector cells(pbmc-treg)were sorted out and cultured alone or together in vitro,and the cell proliferation and cytokines production were measured. serum hbv titers,hbv markers and liver function were also evaluated.results the fraction of circulating cd4+cd25+ treg cells induced in pbmc from chb patients under the stimulation of recombinant hbsag was much higher than that in ahb patients(f=3.47,p＜0.05)and normal controls(f=4.98,p＜0.05).with hbsag stimulation,cell proliferation and cytokines production (ifn-γand il-10)of cd4+ cd25+ treg cells either from patients or from normal controls was very low when cultured alone,and there was no significant difference between two groups(p＞0.05).cell proliferation and ifn-γproduction of effector cells from ahb patients were higher than those from chb patients,however,when effector cells were cultured with cd4+cd25+treg cells at a ratio of 5:1,the cell proliferation and ifn-γ production were significantly inhibited (f=4.66,5.24,p＜0.05).conclusion circulating nificantly suppress the production and ifn-γ production of effector t cells,which may be associated with the progress of chronic hbv infection.