IFN-regulatory factor 3-dependent gene expression is defective in Tbk1-deficient mouse embryonic fibroblasts
IFN-regulatory factor 3-dependent gene expression is defective in Tbk1-deficient mouse embryonic fibroblasts
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DOI：
10.1073/pnas.2237236100
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发表时间：
2004-01-06
影响因子：
11.1
通讯作者：
Maniatis, T
中科院分区：
文献类型：
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作者：
McWhirter, SM;Fitzgerald, KA;Maniatis, T
病毒感染、双链RNA和脂多糖均诱导编码ifn - α和- β的基因和趋化因子的表达，如RANTES（受激活调控，正常T细胞表达和分泌）和IP-10 （ifn - γ诱导蛋白10）。这种诱导需要多种转录因子的协同激活，包括ifn调节因子3 （IRF3）。导致IRF3激活的信号通路是由病原体特异性产物与toll样受体结合触发的，并最终导致IRF3 C端特定丝氨酸残基的磷酸化。最近对培养的人类细胞系的研究表明，两种非规范的IKK激酶（IKK）相关激酶，IKK-epsilon和Traf家族成员相关的NF-kappaB激活物（TANK）结合激酶1 （TBK1）参与IRF3的磷酸化。在这里，我们发现纯化的重组IKK-epsilon和TBK1直接磷酸化IRF3中的关键丝氨酸残基。我们还研究了来自Tbk1（-/-）小鼠的小鼠胚胎成纤维细胞（mef）中IRF3依赖基因的表达，我们发现Tbk1是这些细胞中IRF3激活和核易位所必需的。此外，Tbk1(-/-) mef在感染仙台病病毒或新城病病毒或双链RNA和脂多糖分别接触toll样受体3和4后，ifn - α和- β、IP-10和RANTES基因表达明显缺陷。最后，TRIF（含TIR结构域的适配器诱导ifn - β）无法激活Tbk1(-/-) mef中的irf3依赖性基因。我们认为TBK1对irf3依赖性抗病毒基因的表达至关重要。
Virus infection, double-stranded RNA, and lipopolysaccharide each induce the expression of genes encoding IFN-alpha and -beta and chemokines, such as RANTES (regulated on activation, normal T cell expressed and secreted) and IP-10 (IFN-gamma inducible protein 10). This induction requires the coordinate activation of several transcription factors, including IFN-regulatory factor 3 (IRF3). The signaling pathways leading to IRF3 activation are triggered by the binding of pathogen-specific products to Toll-like receptors and culminate in the phosphorylation of specific serine residues in the C terminus of IRF3. Recent studies of human cell lines in culture have implicated two noncanonical IkappaB kinase (IKK)-related kinases, IKK-epsilon and Traf family member-associated NF-kappaB activator (TANK)-binding kinase 1 (TBK1), in the phosphorylation of IRF3. Here, we show that purified recombinant IKK-epsilon and TBK1 directly phosphorylate the critical serine residues in IRF3. We have also examined the expression of IRF3-dependent genes in mouse embryonic fibroblasts (MEFs) derived from Tbk1(-/-) mice, and we show that TBK1 is required for the activation and nuclear translocation of IRF3 in these cells. Moreover, Tbk1(-/-) MEFs show marked defects in IFN-alpha and -beta, IP-10, and RANTES gene expression after infection with either Sendai or Newcastle disease viruses or after engagement of the Toll-like receptors 3 and 4 by double-stranded RNA and lipopolysaccharide, respectively. Finally, TRIF (TIR domain-containing adapter-inducing IFN-beta), fails to activate IRF3-dependent genes in Tbk1(-/-) MEFs. We conclude that TBK1 is essential for IRF3-dependent antiviral gene expression.