Distinct temporal roles for the promyelocytic leukaemia (PML) protein in the sequential regulation of intracellular host immunity to HSV-1 infection.
Distinct temporal roles for the promyelocytic leukaemia (PML) protein in the sequential regulation of intracellular host immunity to HSV-1 infection.
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DOI：
10.1371/journal.ppat.1006769
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发表时间：
2018-01
期刊：
影响因子：
6.7
通讯作者：
Boutell C
中科院分区：
文献类型：
--
作者：
Alandijany T;Roberts APE;Conn KL;Loney C;McFarlane S;Orr A;Boutell C
病毒核酸检测在诱导细胞内宿主免疫防御中起着至关重要的作用。然而，由于与低基因组拷贝数检测相关的技术困难，免疫调节因子对感染病毒基因组的时间招募仍然不明确。本研究利用单纯疱疹病毒1型（HSV-1） DNA的5-乙基-2′-脱氧尿苷（EdU）标记，结合点击化学来检测宿主免疫调节因子在低多重感染条件下感染病毒基因组的顺序募集。在病毒基因组进入细胞核后，PML-NB核小体（PML-NBs）迅速捕获病毒DNA (vDNA)，导致在病毒PML-NB拮抗剂ICP0缺失的情况下病毒复制受阻。这种预先存在的宿主对感染的内在防御独立于vDNA病原体传感器IFI16（干扰素γ诱导蛋白16）和干扰素刺激基因（ISG）表达的诱导，表明vDNA单独进入细胞核不足以诱导强大的先天免疫反应。在HSV-1 ICP0-null突变体感染期间，这种预先存在的内在宿主防御饱和导致PML和IFI16稳定募集到与ICP4相关的vDNA复合物中，并诱导ISG表达。这种诱导的先天免疫反应以PML-、IFI16-和Janus-Associated Kinase （JAK）依赖的方式发生，并受到膦乙酸的限制，这表明在HSV-1感染期间，vDNA聚合酶活性是诱导ISG表达的必需条件。我们的数据确定了PML在对HSV-1感染的内在免疫和先天免疫的顺序调节中的双重作用，这分别依赖于病毒基因组传递到细胞核和vDNA复制的开始。这些细胞内宿主防御被ICP0抵消，ICP0从核感染开始就靶向PML降解，以促进PML- nbs的vDNA释放和HSV-1裂解复制的开始。内在免疫和先天免疫的作用是限制许多临床上重要的病毒病原体的复制。然而，在病毒感染期间，这两个宿主免疫臂的时间调节仍然不清楚。在疱疹病毒感染期间，这些细胞内免疫防御调节的一个关键方面是组成性表达的免疫调节因子的快速募集来感染病毒基因组。本研究表明，在感染的生理低多样性下，PML-NBs在细胞核进入时迅速捕获HSV-1基因组。这种预先存在的内在宿主防御饱和导致vDNA病原体传感器IFI16稳定地募集到HSV-1 vDNA上，并诱导ISG表达，这是一种依赖于vDNA复制启动的诱导先天免疫反应。重要的是，宿主免疫的固有臂和先天臂都需要PML， PML- nbs的主要支架蛋白。我们的研究确定了PML在HSV-1感染期间细胞内宿主免疫的顺序调节中的双重作用，并强调了宿主免疫因子募集到感染病毒基因组的不同阶段，这是疱疹病毒感染期间细胞内宿主免疫防御的时间调节所必需的。
Detection of viral nucleic acids plays a critical role in the induction of intracellular host immune defences. However, the temporal recruitment of immune regulators to infecting viral genomes remains poorly defined due to the technical difficulties associated with low genome copy-number detection. Here we utilize 5-Ethynyl-2’-deoxyuridine (EdU) labelling of herpes simplex virus 1 (HSV-1) DNA in combination with click chemistry to examine the sequential recruitment of host immune regulators to infecting viral genomes under low multiplicity of infection conditions. Following viral genome entry into the nucleus, PML-nuclear bodies (PML-NBs) rapidly entrapped viral DNA (vDNA) leading to a block in viral replication in the absence of the viral PML-NB antagonist ICP0. This pre-existing intrinsic host defence to infection occurred independently of the vDNA pathogen sensor IFI16 (Interferon Gamma Inducible Protein 16) and the induction of interferon stimulated gene (ISG) expression, demonstrating that vDNA entry into the nucleus alone is not sufficient to induce a robust innate immune response. Saturation of this pre-existing intrinsic host defence during HSV-1 ICP0-null mutant infection led to the stable recruitment of PML and IFI16 into vDNA complexes associated with ICP4, and led to the induction of ISG expression. This induced innate immune response occurred in a PML-, IFI16-, and Janus-Associated Kinase (JAK)-dependent manner and was restricted by phosphonoacetic acid, demonstrating that vDNA polymerase activity is required for the robust induction of ISG expression during HSV-1 infection. Our data identifies dual roles for PML in the sequential regulation of intrinsic and innate immunity to HSV-1 infection that are dependent on viral genome delivery to the nucleus and the onset of vDNA replication, respectively. These intracellular host defences are counteracted by ICP0, which targets PML for degradation from the outset of nuclear infection to promote vDNA release from PML-NBs and the onset of HSV-1 lytic replication. Intrinsic and innate immunity act to restrict the replication of many clinically important viral pathogens. However, the temporal regulation of these two arms of host immunity during virus infection remains poorly defined. A key aspect in the regulation of these intracellular immune defences during herpesvirus infection is the rapid recruitment of constitutively expressed immune regulators to infecting viral genomes. Here we show that at physiologically low multiplicities of infection, PML-NBs rapidly entrap HSV-1 genomes upon nuclear entry. Saturation of this pre-existing intrinsic host defence led to the stable recruitment of the vDNA pathogen sensor IFI16 to HSV-1 vDNA and the induction of ISG expression, an induced innate immune response dependent on the initiation of vDNA replication. Importantly, both intrinsic and innate arms of host immunity required PML, the principle scaffolding protein of PML-NBs. Our research identifies dual roles for PML in the sequential regulation of intracellular host immunity during HSV-1 infection, and highlights distinct phases in host immune factor recruitment to infecting viral genomes required for the temporal regulation of intracellular host immune defences during herpesvirus infection.
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影响因子：
32.4
作者：
Blanco-Melo D;Venkatesh S;Bieniasz PD
通讯作者：
Bieniasz PD
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影响因子：
6.7
作者：
Boutell C;Cuchet-Lourenço D;Vanni E;Orr A;Glass M;McFarlane S;Everett RD
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Everett RD
影响因子：
6.4
作者：
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通讯作者：
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影响因子：
6.7
作者：
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通讯作者：
DeLuca NA
影响因子：
5.4
作者：
Everett, RD;Boutell, C;Orr, A
通讯作者：
Orr, A