Oquendo J, Dubanchet S, Capel F, Mabit H, Petit M A
INSERM U 131, Clamart, France.
Eur Cytokine Netw. 1996 Dec;7(4):793-800.
The major target organ for Hepatitis B Virus (HBV) is the liver, but extrahepatic sites including monocytes express receptors for HBV and may become infected. Therefore, we investigated the effect of HBV on the in vitro expression of interleukin-beta (IL-1 beta) and interleukin-6 (IL-6) by the monocytoid cell line THP-1, exposed to various stimuli (LPS, PMA or both). Nonstimulated THP-1 cells did not synthesize IL-1 beta and IL-6, even after in vitro exposure to HBV. LPS stimulation alone induced moderate secretion of both IL-1 beta and IL-6 (300 pg/ml). After induction of macrophage differentiation by PMA, THP-1 cells acquired adherence and expressed a higher level of IL-1 beta (up to 2 ng/ml) but did not synthesize IL-6. Treatment of THP-1 cells with PMA and LPS caused the highest production of both IL-1 beta and IL-6 (> 5ng/ml). In vitro exposure of PMA + LPS-stimulated THP-1 cells to HBV resulted in secretion of both HBsAg and preS2Ag which was maintained over 10 days of culture. Southern blot technique was used to study the state of HBV DNA in the cells. Hybridization of non-digested cellular DNA showed only high molecular weight HBV DNA forms. The HindIII restriction pattern revealed bands corresponding to large DNA fragments and the presence of bands at the 3.2 kb position. Under these conditions (PMA + LPS), HBV inhibited the production of IL-1 beta and IL-6 proteins and completely suppressed the IL-1 beta and IL-6 mRNA. Thus, our findings (i) strongly support a relationship between the state of cell differentiation and susceptibility of cells to HBV infection, and (ii) demonstrate that HBV exerts an inhibitory effect on the induction of IL-1 beta and IL-6 genes expression in monocytic THP-1 cells. These results suggest that HBV leads to a fall of pro-inflammatory cytokine production by monocytes/macrophages, which may contribute to impaired host immune response during infection.
乙型肝炎病毒（HBV）的主要靶器官是肝脏，但包括单核细胞在内的肝外部位表达HBV受体并可能被感染。因此，我们研究了HBV对单核细胞系THP-1在体外表达白细胞介素-β（IL-1β）和白细胞介素-6（IL-6）的影响，该细胞系暴露于各种刺激物（脂多糖、佛波酯或两者）。未受刺激的THP-1细胞即使在体外暴露于HBV后也不合成IL-1β和IL-6。单独的脂多糖刺激诱导IL-1β和IL-6适度分泌（300 pg/ml）。经佛波酯诱导巨噬细胞分化后，THP-1细胞获得黏附性并表达更高水平的IL-1β（高达2 ng/ml），但不合成IL-6。用佛波酯和脂多糖处理THP-1细胞导致IL-1β和IL-6产生量最高（>5 ng/ml）。将经佛波酯 + 脂多糖刺激的THP-1细胞在体外暴露于HBV导致HBsAg和前S2Ag分泌，且在培养10天以上时持续存在。采用Southern印迹技术研究细胞中HBV DNA的状态。未消化的细胞DNA杂交仅显示高分子量HBV DNA形式。HindIII酶切图谱显示对应于大DNA片段的条带以及在3.2 kb位置有条带。在这些条件下（佛波酯 + 脂多糖），HBV抑制IL-1β和IL-6蛋白的产生并完全抑制IL-1β和IL-6 mRNA。因此，我们的发现（i）有力地支持了细胞分化状态与细胞对HBV感染易感性之间的关系，并且（ii）证明HBV对单核细胞THP-1细胞中IL-1β和IL-6基因表达的诱导具有抑制作用。这些结果表明，HBV导致单核细胞/巨噬细胞促炎细胞因子产生减少，这可能导致感染期间宿主免疫反应受损。
