Herpes simplex virus type 1 Us3 gene deletion influences toll-like receptor responses in cultured monocytic cells.
Herpes simplex virus type 1 Us3 gene deletion influences toll-like receptor responses in cultured monocytic cells.
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DOI：
10.1186/1743-422x-5-140
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发表时间：
2008-11-21
期刊：
影响因子：
4.8
通讯作者：
Hukkanen V
中科院分区：
文献类型：
--
作者：
Peri P;Mattila RK;Kantola H;Broberg E;Karttunen HS;Waris M;Vuorinen T;Hukkanen V
toll样受体在微生物感染的先天免疫应答中起关键作用。toll样受体（TLR）家族由10个已确定的人类TLR组成，其中TLR2和TLR9已被证明可启动对1型单纯疱疹病毒（HSV-1）的先天反应，TLR3已被证明参与防御中枢神经系统的严重HSV-1感染。然而，在野生型HSV-1感染中未观察到TLR3通路的显著激活。在这项工作中，我们研究了Us3和ICP4基因缺失的HSV-1对TLR的反应及其对TLR基因表达的影响，并在人单核细胞（U937）培养中引起感染细胞凋亡。用Us3和ICP4缺失型单纯疱疹病毒（d120）、其亲本病毒HSV-1 （KOS）、Us3缺失型病毒（R7041）、其拯救型病毒（R7306）或野生型HSV-1 (F)感染U937人单核细胞。采用实时荧光定量PCR分析各组TLR2、TLR3、TLR4、TLR9及I型干扰素（IFN） mRNA表达情况。流式细胞术检测细胞内TLR3和I型IFN诱导的黏液病毒抗性蛋白A （MxA）蛋白的表达及细胞凋亡水平。我们观察到，在d120、R7041和HSV-1 (F)感染的U937细胞中，TLR3和I型ifn的mRNA表达显著升高。此外，在d120和r7041感染的细胞中，细胞内TLR3和MxA的表达显著升高。我们观察到IRF-3在d120和R7041感染中被激活。与未感染细胞相比，d120和r7041感染细胞的TLR4 mRNA表达水平显著降低，而HSV-1 （KOS）感染细胞的TLR4 mRNA表达水平升高。TLR2和TLR9 mRNA表达水平无显著差异。R7041和d120病毒均能诱导U937细胞凋亡。与未感染细胞相比，d120、R7041和HSV-1 (F)感染细胞的TLR3和I型IFN mRNA水平升高。IRF-3在感染Us3基因缺失病毒d120和R7041的细胞中也被激活。这与细胞中TLR3信号的激活是一致的。在感染d120和r7041的细胞中，细胞内TLR3和I型IFN诱导的MxA蛋白水平升高，而在感染相应亲本病毒或救援病毒的细胞中则没有升高，这表明HSV-1 Us3基因参与了U937细胞中TLR3反应的控制。
Toll-like receptors have a key role in innate immune response to microbial infection. The toll-like receptor (TLR) family consists of ten identified human TLRs, of which TLR2 and TLR9 have been shown to initiate innate responses to herpes simplex virus type 1 (HSV-1) and TLR3 has been shown to be involved in defence against severe HSV-1 infections of the central nervous system. However, no significant activation of the TLR3 pathways has been observed in wild type HSV-1 infections. In this work, we have studied the TLR responses and effects on TLR gene expression by HSV-1 with Us3 and ICP4 gene deletions, which also subject infected cells to apoptosis in human monocytic (U937) cell cultures. U937 human monocytic cells were infected with the Us3 and ICP4 deletion herpes simplex virus (d120), its parental virus HSV-1 (KOS), the Us3 deletion virus (R7041), its rescue virus (R7306) or wild type HSV-1 (F). The mRNA expression of TLR2, TLR3, TLR4, TLR9 and type I interferons (IFN) were analyzed by quantitative real-time PCR. The intracellular expression of TLR3 and type I IFN inducible myxovirus resistance protein A (MxA) protein as well as the level of apoptosis were analyzed by flow cytometry. We observed that the mRNA expression of TLR3 and type I IFNs were significantly increased in d120, R7041 and HSV-1 (F)-infected U937 cells. Moreover, the intracellular expression of TLR3 and MxA were significantly increased in d120 and R7041-infected cells. We observed activation of IRF-3 in infections with d120 and R7041. The TLR4 mRNA expression level was significantly decreased in d120 and R7041-infected cells but increased in HSV-1 (KOS)-infected cells in comparison with uninfected cells. No significant difference in TLR2 or TLR9 mRNA expression levels was seen. Both the R7041 and d120 viruses were able to induce apoptosis in U937 cell cultures. The levels of TLR3 and type I IFN mRNA were increased in d120, R7041 and HSV-1 (F)-infected cells when compared with uninfected cells. Also IRF-3 was activated in cells infected with the Us3 gene deletion viruses d120 and R7041. This is consistent with activation of TLR3 signaling in the cells. The intracellular TLR3 and type I IFN inducible MxA protein levels were increased in d120 and R7041-infected cells but not in cells infected with the corresponding parental or rescue viruses, suggesting that the HSV-1 Us3 gene is involved in control of TLR3 responses in U937 cells.