HBeAg对树突细胞分泌白细胞介素6和12的影响

Hepatitis B e antigen perturbs the LPS-stimulated production of inflammatory cytokines by mononuclear- derived dendritic cells

目的研究HBeAg对脂多糖（LPs）诱导树突细胞（DCs）分泌炎症因子自细胞介素（IL）-12和IL-6的影响。方法密度梯度离心法分离浓缩白细胞获得单个核细胞，经贴壁法纯化的单核细胞由刺激因子诱导得到未成熟DCs，形态学观察及免疫表型鉴定DCs；加入不同浓度（1、2、5μg／m1）HBeAg，LPS刺激摄取抗原的DCs，酶联免疫法测定培养上清液中IL-12和IL-6水平。细胞表型比较用Mann-WhitneyU检验，不同浓度组间数据的多重比较用LSD-t检验（方差齐）或Dunnett’sT3检验（方差不齐）。结果HBeAg1、2、5μg／ml组及对照组上清液的IL-6分泌水平分别为（1177．64±167．38）pg／ml、（1092．88±60．90）pg／ml、（793．65±96．29）pg／ml和（1612．38土244．59）pg／ml，HBeAg1、2、5μg／m]组的IL-6水平均低于对照组，差异有统计学意义（f值分别为3．35、4．00和6．32，P〈0．05或P〈0．01），HBeAg1μg／ml组IL-6分泌水平明显高于5μg／ml组（f=2．96，P〈0．05）；HBeAg1、2、5μg／ml组及对照组上清液的IL-12分泌水平分别为（1037．64土58．46）pg／ml、（885．31±13．00）pg／ml、（804．34士15．25）pg／ml和（1101．46±30．76）pg／ml，HBeAg1μg／ml组与对照组的IL-12分泌水平差异无统计学意义（t=1．67，P〉0．05），2ug／ml和5μg／ml组IL-12分泌水平较对照组明显下调（t值分别为11．21和14．99，P值均〈0．01），5Hg／ml组IL-12分泌水平明显低于2μg／ml组（f=7．00，P〈0．05）。结论HBeAg能下调Des分泌炎症因子IL—12和IL-6，这可能是HBV持续感染的免疫逃逸机制之一。

Objective To investigate whether hepatitis B e antigen （HBeAg） can modulate the ability of dendritic cells （DCs） to produce inflammatory cytokines （IL-12/IL-6） upon stimulation in vitro. Methods Purified adherent mononuclear cells isolated by Ficoll-hypaque density gradient centrifugation were cultured in complete medium containing granulocyte macrophage colony-stimulating factor plus interleukin （IL）-4 to generate immature （i）DCs. Microscopic analysis and flow cytometry were performed to define the phenotypic characteristics of the iDCs. Then, different concentrations （1, 2 and 5 μg/ml） of HBeAg were added to the culture medium and for 24 hrs of incubation. To induce iDCs＇ maturation, the various groups of cells were incubated for 24 hrs in differentiation culture with lipopolysaccharide （LPS）. Effects on secreted inflammatory cytokines were determined by enzyme-linked immunosorbent assay of the cells＇ supernatants. Results All concentrations of HBeAg led to significant reductions in IL-6 （all P 〈 0.05）. Similar significant reductiontrends were seen for IL-12 at the HBeAg concentrations of 2 and 5 μg/ml （bothP 〈 0.05）, but not at the 1μg/ ml concentration. Conclusion HBeAg may suppress the production of cytokines from DCs; this mechanism may contribute to the immune escape of HBV that supports persistent infection.