Synoviocyte innate immune responses: II. Pivotal role of IFN regulatory factor 3.
Synoviocyte innate immune responses: II. Pivotal role of IFN regulatory factor 3.
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DOI：
10.4049/jimmunol.0903944
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发表时间：
2010-06-15
期刊：
影响因子：
--
通讯作者：
Firestein GS
中科院分区：
文献类型：
--
作者：
Sweeney SE;Kimbler TB;Firestein GS
先天免疫反应可能导致类风湿性关节炎（RA）滑膜炎症。在与 RA 相关的先天受体中，TLR3 激活多个信号级联，包括 β-干扰素调节因子 3 和 7 (IRF)，从而产生病毒应激 IFN 诱导基因。本研究旨在研究 IRF3 和 IRF7 对 I 型 IFN 反应的贡献以及滑膜细胞中其他细胞因子、趋化因子和降解酶的表达。用 IRF3 或 IRF7 siRNA 转染后，用聚 (I-C) 刺激成纤维细胞样滑膜细胞 (FLS) 以敲低转录因子表达。进行蛋白质印迹、转染报告构建体后的荧光素酶测定、Q-PCR 和 AP-1 DNA 结合 ELISA，以评估 IRF3 和 IRF7 在聚 (I-C) 诱导的信号传导和滑膜细胞基因表达中的作用。 IRF3 和 IRF7 敲低表明，IRF3 响应聚 (I-C) 调节 IFN 刺激反应元件 (ISRE) 启动子活性以及 IFNβ、IRF5、IRF7、RANTES、IP-10、MCP-1 和 MIP1α 基因表达。 IRF7 敲除适度降低了一部分基因和 ISRE 活性，但结果并不显着。令人惊讶的是，IRF3 敲低几乎完全阻断了其他基因的表达，其中 ISRE 传统上不被认为是 FLS 中的显性启动子位点，包括 MMP3、MMP9、IL-6 和 IL-8。然后我们研究了 IRF3 在 c-Jun 激活和 AP-1 结合中的可能作用，因为它的启动子位点存在于所有四个非 IFN 调节的基因中。与对照相比，IRF3 缺陷显着降低了活化的 c-Jun 的 AP-1 结合。与免疫细胞相反，IRF3 而不是 IRF7 调节人类滑膜细胞中 TLR3 介导的 I 型 IFN 反应。 IRF3 通过增加 ISRE 启动子活性来激活 IFN 反应基因表达。此外，IRF3 通过涉及 c-Jun 和 AP-1 启动子位点的新机制调节其他细胞因子、趋化因子和 MMP。由于 IRF3 调节的信号通路在滑膜细胞中发挥着至关重要的作用，因此靶向 IRF3 代表了一种抑制多种介质同时限制对 IRF7 介导的免疫反应的抑制的潜在方法。
Innate immune responses likely contribute to synovial inflammation in rheumatoid arthritis (RA). Of the innate receptors implicated in RA, TLR3 activates several signaling cascades, including -interferon regulatory factors 3 and 7 (IRF), resulting in production of viral-stress IFN-inducible genes. The present study was designed to investigate the contributions of IRF3 and IRF7 to the type I IFN response as well as the expression of other cytokines, chemokines, and degradative enzymes in synoviocytes. Fibroblast-like synoviocytes (FLS) were stimulated with poly (I-C) after transfection with IRF3 or IRF7 siRNA to knockdown transcription factor expression. Western blots, luciferase assay after transfection with reporter constructs, Q-PCR, and AP-1 DNA binding ELISA was performed to evaluate the role of IRF3 and IRF7 in poly (I-C)-induced signaling and synoviocyte gene expression. IRF3 and IRF7 knockdown showed that IRF3 regulates IFN-stimulated response element (ISRE) promoter activity as well as IFNβ, IRF5, IRF7, RANTES, IP-10, MCP-1, and MIP1α gene expression in response to poly (I-C). IRF7 knockdown modestly decreased a subset of genes and ISRE activity, although the results were not significant. Surprisingly, IRF3 knockdown almost completely blocked expression of additional genes in which the ISRE is not traditionally considered a dominant promoter site in FLS, including MMP3, MMP9, IL-6 and IL-8. We then investigated a possible role for IRF3 in c-Jun activation and AP-1 binding because its promoter site is present in all four of the non-IFN regulated genes. IRF3 deficiency significantly decreased AP-1 binding of activated c-Jun compared with control. In contrast to immune cells, IRF3 rather than IRF7 regulates TLR3-mediated type I IFN responses in human synoviocytes. IRF3 activates IFN-response gene expression by increasing ISRE promoter activity. In addition, IRF3 regulates other cytokines, chemokines, and MMPs through a novel mechanism that involves c-Jun and the AP-1 promoter site. Because the signaling pathway modulated by IRF3 plays a crucial role in synoviocytes, targeting IRF3 represents a potential approach to suppress diverse mediators while limiting suppression of IRF7-mediated immune responses.
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影响因子：
27.4
作者：
van Holten, J;Pavelka, K;Tak, PP
通讯作者：
Tak, PP
影响因子：
--
作者：
García-Vicuña, R;Gómez-Gaviro, MV;Díaz-González, F
通讯作者：
Díaz-González, F
影响因子：
27.4
作者：
Corr M;Boyle DL;Ronacher L;Flores N;Firestein GS
通讯作者：
Firestein GS
影响因子：
--
作者：
Brentano, F;Schorr, O;Kyburz, D
通讯作者：
Kyburz, D
影响因子：
--
作者：
Roelofs, MF;Joosten, LAB;Radstake, TRDJ
通讯作者：
Radstake, TRDJ