Ataxia Telangiectasia Mutated Kinase Mediates NF-κB Serine 276 Phosphorylation and Interferon Expression via the IRF7-RIG-I Amplification Loop in Paramyxovirus Infection
Ataxia Telangiectasia Mutated Kinase Mediates NF-κB Serine 276 Phosphorylation and Interferon Expression via the IRF7-RIG-I Amplification Loop in Paramyxovirus Infection
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DOI：
10.1128/jvi.02458-14
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发表时间：
2015-03-01
影响因子：
5.4
通讯作者：
Brasier, Allan R.
中科院分区：
文献类型：
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作者：
Fang, Ling;Choudhary, Sanjeev;Brasier, Allan R.
呼吸道合胞病毒(RSV)是儿童下呼吸道疾病的主要病原体。活动性感染诱导的分子模式触发协调的维甲酸诱导基因I(RIG-I)-Toll样受体(TLR)信号反应，诱导炎性细胞因子和抗病毒黏膜干扰素。最近，我们在细胞因子诱导的核因子-kappaB/rela Ser276的磷酸化过程中发现了一个由DNA损伤反应蛋白共济失调毛细血管扩张突变(ataxia毛细血管扩张突变，ATM)介导的核氧化应激敏感通路。在这里，我们观察到ATM沉默导致RSV和仙台病毒的单链RNA(SsRNA)复制增强，这是由于I型和III型干扰素(IFN)的表达和分泌减少，尽管维持了依赖于干扰素调节因子3(IRF3)的干扰素刺激基因(ISGs)。除了增强的氧化应激外，RSV复制还增强了组蛋白2AX磷酸化变异体(Gamma H2AX)的焦点，ATM的Ser1981磷酸化，以及依赖ikk Gamma/Nemo的ATM核输出，表明DNA损伤反应被激活。ATM缺陷细胞表现出RSV诱导的丝裂原和应激激活蛋白1(MSK-1)Ser376的磷酸化和Rela Ser276的磷酸化降低，这是IRF7表达所必需的。我们观察到，RERA以ATM依赖的方式诱导结合天然干扰素调节因子7(IRF7)启动子，而IRF7可诱导结合内源性维甲酸诱导基因I(RIG-I)启动子。异位表达IRF7可恢复ATM沉默细胞的RIG-I表达和I/III型干扰素表达。我们得出结论，副粘病毒触发DNA损伤反应，这是MSK1激活磷酸化Ser276relA所需的途径，以触发粘膜产生干扰素所必需的IRF7-RIG-I扩增环。这些数据为ATM纯合子突变患者的细胞天然免疫缺陷提供了分子发病机制。IMPORTANCERNA病毒感染触发细胞反应途径，限制传播到邻近组织。这种“先天免疫反应”是由生殖系编码的模式识别受体介导的，它触发了两个基本上独立的细胞内核因子-kappaB和IRF3转录因子的激活。在下游，保护性抗病毒干扰素的表达由可诱导的干扰素调节因子(IRF)和维甲酸诱导基因(RIG-I)介导的正反馈环扩增。我们的结果表明，需要一种核氧化应激和DNA损伤敏感因子ATM，通过介导NF-kappa B的磷酸化来介导NF-kappa B和IRF7之间的串扰通路。我们的研究为遗传性ATM突变患者的细胞和天然免疫缺陷提供了进一步的信息。
Respiratory syncytial virus (RSV) is a primary etiological agent of childhood lower respiratory tract disease. Molecular patterns induced by active infection trigger a coordinated retinoic acid-inducible gene I (RIG-I)-Toll-like receptor (TLR) signaling response to induce inflammatory cytokines and antiviral mucosal interferons. Recently, we discovered a nuclear oxidative stress-sensitive pathway mediated by the DNA damage response protein, ataxia telangiectasia mutated (ATM), in cytokine-induced NF-kappa B/RelA Ser 276 phosphorylation. Here we observe that ATM silencing results in enhanced single-strand RNA (ssRNA) replication of RSVand Sendai virus, due to decreased expression and secretion of type I and III interferons (IFNs), despite maintenance of IFN regulatory factor 3 (IRF3)-dependent IFN-stimulated genes (ISGs). In addition to enhanced oxidative stress, RSV replication enhances foci of phosphorylated histone 2AX variant (gamma H2AX), Ser 1981 phosphorylation of ATM, and IKK gamma/NEMO-dependent ATM nuclear export, indicating activation of the DNA damage response. ATM-deficient cells show defective RSV-induced mitogen and stress-activated kinase 1 (MSK-1) Ser 376 phosphorylation and reduced RelA Ser 276 phosphorylation, whose formation is required for IRF7 expression. We observe that RelA inducibly binds the native IFN regulatory factor 7 (IRF7) promoter in an ATM-dependent manner, and IRF7 inducibly binds to the endogenous retinoic acid-inducible gene I (RIG-I) promoter. Ectopic IRF7 expression restores RIG-I expression and type I/III IFN expression in ATM-silenced cells. We conclude that paramyxoviruses trigger the DNA damage response, a pathway required for MSK1 activation of phospho Ser 276 RelA formation to trigger the IRF7-RIG-I amplification loop necessary for mucosal IFN production. These data provide the molecular pathogenesis for defects in the cellular innate immunity of patients with homozygous ATM mutations.IMPORTANCERNA virus infections trigger cellular response pathways to limit spread to adjacent tissues. This "innate immune response" is mediated by germ line-encoded pattern recognition receptors that trigger activation of two, largely independent, intracellular NF-kappa B and IRF3 transcription factors. Downstream, expression of protective antiviral interferons is amplified by positive-feedback loops mediated by inducible interferon regulatory factors (IRFs) and retinoic acid inducible gene (RIG-I). Our results indicate that a nuclear oxidative stress-and DNA damage-sensing factor, ATM, is required to mediate a cross talk pathway between NF kappa B and IRF7 through mediating phosphorylation of NF-kappa B. Our studies provide further information about the defects in cellular and innate immunity in patients with inherited ATM mutations.