Expression of Toll-like receptors in chronic hepatitis C virus infection
Expression of Toll-like receptors in chronic hepatitis C virus infection
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DOI：
10.1111/j.1440-1746.2006.04783.x
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发表时间：
2007-10-01
影响因子：
4.1
通讯作者：
Kakumu, Shinichi
中科院分区：
文献类型：
--
作者：
Sato, Ken;Ishikawa, Tetsuya;Kakumu, Shinichi
背景：Toll样受体(TLRs)参与先天免疫。某些病毒与TLRs相互作用，并介导抗病毒作用和免疫反应。方法：采用实时荧光定量聚合酶链式反应技术检测25例慢性肝病患者外周血单个核细胞(PBMC)和CD14+(单核细胞)或CD14-细胞及15例健康体检者外周血中TLRs 2-9和细胞因子的表达。然后用完整或部分(CORE-NS3、NS3-NS5B)的丙型肝炎病毒开放阅读框(CORE-NS3、NS3-NS5B)转染HepG2细胞，检测TLR的表达。结果：患者外周血中CD14+细胞TLR4、7、8的表达均明显升高。患者PBMC的肿瘤坏死因子-α、白介素6和白介素12p35水平也升高。当PBMC与丙型肝炎病毒核心蛋白共同孵育时，患者TLR2表达增强，TLR4和TLR7表达抑制。对照组中也观察到类似的TLRs表达变化。在HepG2转染组中，只有TLR3的表达发生改变，全基因转染组TLR3表达受到抑制，CORE-NS3转染组TLR3表达增强。结论：TLRs和细胞因子的表达水平与慢性丙型肝炎病毒感染密切相关。TLR3识别双链RNA，诱导1型干扰素合成。总之，在整个丙型肝炎病毒感染的细胞中，TLR3的表达被抑制可能是持续的丙型肝炎病毒感染的原因，尽管一部分丙型肝炎病毒基因增强了它的表达。
Background: Toll-like receptors (TLRs) are involved in innate immunity. Certain viruses interact with TLRs and mediate antiviral effects as well as immune responses. The aim of this study was to investigate the effect of TLRs on pathogenesis in hepatitis C virus (HCV)-infected patients.Methods: Peripheral blood mononuclear cells (PBMC) and CD14+ (monocytes) or CD14- cells from 25 patients with chronic liver disease and 15 healthy subjects were studied for expression of TLRs 2-9 and cytokines of extracted RNA using real-time PCR. Then TLR expression was examined in HepG2 cells transfected with entire or parts (core-NS3, NS3-NS5B) of the HCV open reading frame. TLR expression was calculated as the relative mRNA levels.Results: Expression of TLRs 4, 7 and 8 in CD14+ cells of PBMC was increased in patients. Levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-12 p35 for PBMC were also increased in patients. When PBMC were incubated with HCV core protein, enhancement of TLR2 expression and suppression of TLR4 and TLR7 were noted in patients. Similar alteration of TLRs expression was observed in controls. Among HepG2 transfectants, only TLR3 expression was changed; it was suppressed in entire gene transfectant and enhanced in core-NS3 transfectant. Expression of some proteins related to the TLR signaling pathway was suppressed in the entire gene transfectant.Conclusions: The results suggest a correlation between expression levels of TLRs and cytokines, and chronic HCV infection. TLR3 recognizes double-stranded RNA and induces type 1 interferon synthesis. Collectively, suppressed expression of TLR3 in cells transfected with entire HCV may be responsible for continuous HCV infection, although a part of the HCV gene enhances its expression.