STAT and Janus kinase targeting by human herpesvirus 8 interferon regulatory factor in the suppression of type-I interferon signaling.
STAT and Janus kinase targeting by human herpesvirus 8 interferon regulatory factor in the suppression of type-I interferon signaling.
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DOI：
10.1371/journal.ppat.1010676
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发表时间：
2022-07
期刊：
影响因子：
6.7
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中科院分区：
文献类型：
--
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人类疱疹病毒8型（HHV-8），也被称为卡波西肉瘤（KS）相关疱疹病毒，在病因学上参与艾滋病相关KS，原发性渗出性淋巴瘤（PEL）和多中心Castleman病，其中病毒潜伏和裂解功能都很重要。HHV-8编码四种病毒干扰素调节因子（vIRF），据信这些因子有助于病毒潜伏（至少在PEL细胞中）和/或通过抑制细胞抗病毒和应激信号传导来促进生产性复制。在这里，我们确定vIRF-1与信号转导和转录激活因子（STAT）因子1和2，干扰素（IFN）刺激的基因因子3（ISGF 3）辅因子IRF 9，以及相关的信号转导Janus激酶JAK 1和TYK 2的相互作用。在自然感染的PEL细胞和用基因工程HHV-8实验感染的iSLK上皮细胞中，vIRF-1消耗或消融分别导致IFNβ处理和未处理的细胞在裂解性复制期间活性（磷酸化）STAT 1和STAT 2水平增加，并导致相关的细胞基因诱导。在用于机制研究的转染的293 T细胞中，发现vIRF-1对IFNβ诱导的磷酸化STAT 1（pSTAT 1）的抑制高度依赖于STAT 2，表明vIRF-1介导的ISGF 3复合物的抑制和/或解离，导致pSTAT 1对失活去磷酸化的敏感性。事实上，涉及ISGF 3组分的靶向沉淀的共沉淀实验鉴定了vIRF-1对相互作用的抑制。相比之下，IFNβ诱导的pSTAT 2的抑制通过调节STAT 2活化来实现，可能是通过检测到TYK 2的抑制及其与STAT 2和IFN I型受体（IFNAR）的相互作用。我们鉴定的vIRF-1与IFN信号传导介质STAT 1和2、共相互作用的ISGF 3组分IRF 9和STAT活化TYK 2的相互作用以及通过ISGF 3、TYK 2-STAT 2和TYK 2-IFNAR破坏和TYK 2抑制的IFN信号传导的抑制代表了vIRF功能和HHV-8逃避宿主细胞防御的新机制。由卡波西肉瘤和淋巴瘤相关的人疱疹病毒8（HHV-8）编码的病毒干扰素调节因子（vIRF）是保护免受细胞抗病毒应答的介质，因此被认为是成功的从头感染、潜伏期建立和维持以及生产性（裂解性）复制的关键。鉴定和表征它们与细胞蛋白的相互作用、这些相互作用的功能后果以及这些机制在感染背景下的操作，有可能开发针对这些相互作用和机制的新型抗病毒策略。在本报告中，我们鉴定了vIRF-1与转录因子STAT 1和STAT 2的相互作用，抗病毒干扰素（IFN）诱导的转录复合物ISGF 3的共相互作用组分IRF 9，以及vIRF-1抑制IFN-1受体和STAT 1/2激酶TYK 2的激活和功能关联，抑制STAT 1/2激活，并将STAT 1从IFN诱导的ISGF 3中解离，以钝化IFN信号传导并促进STAT 1失活。这些相互作用和活动，介导抑制先天性细胞防御病毒复制，代表vIRF之间的新特性，并可能被开发用于抗病毒和治疗目的。
Human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma (KS)-associated herpesvirus, is involved etiologically in AIDS-associated KS, primary effusion lymphoma (PEL), and multicentric Castleman’s disease, in which both viral latent and lytic functions are important. HHV-8 encodes four viral interferon regulatory factors (vIRFs) that are believed to contribute to viral latency (in PEL cells, at least) and/or to productive replication via suppression of cellular antiviral and stress signaling. Here, we identify vIRF-1 interactions with signal transducer and activator of transcription (STAT) factors 1 and 2, interferon (IFN)-stimulated gene factor 3 (ISGF3) cofactor IRF9, and associated signal transducing Janus kinases JAK1 and TYK2. In naturally infected PEL cells and in iSLK epithelial cells infected experimentally with genetically engineered HHV-8, vIRF-1 depletion or ablation, respectively, led to increased levels of active (phosphorylated) STAT1 and STAT2 in IFNβ-treated, and untreated, cells during lytic replication and to associated cellular-gene induction. In transfected 293T cells, used for mechanistic studies, suppression by vIRF-1 of IFNβ-induced phospho-STAT1 (pSTAT1) was found to be highly dependent on STAT2, indicating vIRF-1-mediated inhibition and/or dissociation of ISGF3-complexing, resulting in susceptibility of pSTAT1 to inactivating dephosphorylation. Indeed, coprecipitation experiments involving targeted precipitation of ISGF3 components identified suppression of mutual interactions by vIRF-1. In contrast, suppression of IFNβ-induced pSTAT2 was effected by regulation of STAT2 activation, likely via detected inhibition of TYK2 and its interactions with STAT2 and IFN type-I receptor (IFNAR). Our identified vIRF-1 interactions with IFN-signaling mediators STATs 1 and 2, co-interacting ISGF3 component IRF9, and STAT-activating TYK2 and the suppression of IFN signaling via ISGF3, TYK2-STAT2 and TYK2-IFNAR disruption and TYK2 inhibition represent novel mechanisms of vIRF function and HHV-8 evasion from host-cell defenses. Viral interferon regulatory factors (vIRFs) encoded by Kaposi’s sarcoma- and lymphoma-associated human herpesvirus 8 (HHV-8) are mediators of protection from cellular antiviral responses and therefore are considered to be pivotal for successful de novo infection, latency establishment and maintenance, and productive (lytic) replication. Identification and characterization of their interactions with cellular proteins, the functional consequences of these interactions, and the operation of these mechanisms in the context of infection has the potential to enable the development of novel antiviral strategies targeted to these interactions and mechanisms. In this report we identify vIRF-1 interactions with transcription factors STAT1 and STAT2, the co-interacting component, IRF9, of the antiviral interferon (IFN)-induced transcription complex ISGF3, and the ability of vIRF-1 to inhibit activation and functional associations of IFN-I receptor- and STAT1/2-kinase TYK2, suppress STAT1/2 activation, and dissociate STAT1 from IFN-induced ISGF3 to blunt IFN signaling and promote STAT1 inactivation. These interactions and activities, which mediate suppression of innate cellular defenses against virus replication, represent novel properties among vIRFs and could potentially be exploited for antiviral and therapeutic purposes.
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影响因子：
16
作者：
Davis, Zoe H.;Verschueren, Erik;Jang, Gwendolyn M.;Kleffman, Kevin;Johnson, Jeffrey R.;Park, Jimin;Von Dollen, John;Maher, M. Cyrus;Johnson, Tasha;Newton, William;Jaeger, Stefanie;Shales, Michael;Horner, Julie;Hernandez, Ryan D.;Krogan, Nevan J.;Glaunsinger, Britt A.
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Glaunsinger, Britt A.
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5.4
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4.8
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影响因子：
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