Background Host immune responses against hepatitis B virus （HBV） induced by antiviral therapy play a crucial role in viral clearance. To further investigate the immune mechanisms underlying the differences between respondents and non-respondents, we analyzed myeloid dendritic cells （mDCs）, plasmacytoid dendritic cells （pDCs）, FoxP3＋ regulatory T cells （FoxP3＋ Treg） and programmed death 1 （PD-1） expression in CD4＋/CD8＋ T cells in chronic hepatitis B patients undergoing pegylated interferon （PeglFN）α-2b treatment. Methods Patients received PeglFNα-2b for 24 or 48 weeks, with follow-up at 24 weeks. The frequencies of mDCs, pDCs, FoxP3＋ Treg, and PD-1 expression by CD4＋/CD8＋ T cells were evaluated by flow cytometry at baseline, weeks 4 and 12, end of treatment, and follow-up （12/24 weeks）. Results In HBeAg seroconverters （respondents）, the mDC relative frequency decreased at week 4 and then rebounded at week 12. The pDC relative frequency decreased consistently. In non-HBeAg seroconverters （non-respondents）, both mDC and pDC frequencies decreased slightly. The FoxP3＋ Treg relative frequency decreased during treatment and remained low during follow-up in respondents, while in non-respondents it decreased slightly during therapy but rebounded after discontinuation. In patients with HBeAg 〈17.55 PEI-U/ml at week 12 and 〈8.52 PEI-U/ml at week 24, the FoxP3＋ Treg frequency decreased during treatment and at follow-up. In respondents, CD4~PD-1 and CD8＋PD-1 levels decreased at week 4 and remained low at week 12. In non-respondents, PD-1 expression decreased at week 4 but rebounded at week 12. Conclusions The results indicate that the dynamic changes in DCs, FoxP3＋ Treg frequency, and PD-1 expression by CD4＋ and CD8＋ T cells exhibit different trends in HBeAg and non-HBeAg seroconversion patients. During PeglFNa-2b treatment of chronic hepatitis B patients, these changes may be of predictive value for HBeAg seroconversion. HBsAg and HBeAg levels are related to
目的 研究细胞人基因组DNA 对荧光实时定量PCR(FQ-PCR)检测细胞培养上清液中HBV DNA 含量的可能干扰影响,提高细胞培养上清液中HBV DNA 定量检测的准确性.方法 取HBV DNA 阳性血清,以DMEM 培养基分别配制出HBV DNA 拷贝数为5×107/ml(高拷贝组)、5×105/ml(中拷贝组)、5×103/ml(低拷贝组)的不同样本组;各组内再分5 个亚组,分别加入终浓度为0(对照组)、12.5、25、50、100 μg/ml 的细胞人基因组DNA(提取自人肝癌细胞系HepG2).以不含HBV DNA 阳性血清的DMEM 培养基加入上述浓度细胞人基因组DNA 为空白组.采用基于TaqMan 技术的FQ-PCR 检测各组样本的HBV DNA 拷贝数并绘制HBV DNA 定量曲线.每组均重复检测10 次.根据HBV DNA 定量检测结果确定受干扰样本和未受干扰样本,分别计算其定量曲线线性期斜率和平均扩增效率.结果 高拷贝组中加入不同浓度细胞人基因组DNA 的各个亚组与相应对照组比较,HBV DNA 拷贝数差异均无统计学意义.中拷贝组中加入细胞人基因组DNA 浓度为50和100 μg/ml 的2个亚组,其HBV DNA 拷贝数结果明显高于相应对照组,增高可达50～100倍,且重复性差.低拷贝组中只有加入细胞人基因组DNA 浓度为12.5μg/ml的亚组可通过提高基线值取得与相应对照组接近的定量检测结果,而其他亚组HBV DNA 定量曲线指数扩增期斜率明显异常,无法确定其定量检测结果.空白组各亚组均未观察到明显的HBV DNA 指数扩增期.受干扰样本线性期斜率(-1.01±0.06)和平均扩增效率(90.0%±2.1%)与对照组样本(分别为-1.52±0.06,97.0%±0.4%)比较,差异均有统计学意义(P＜0.01).结论 细胞人基因组DNA 对应用FQ-PCR 技术进行的HBV DNA 定量检测可产生非特异性干扰,尤其在HBVDNA 拷贝水平较低时.在细胞培养上清液作HBV DNA 定量检测时应尽量去除细胞人基因组DNA.
