African Swine Fever Virus Armenia/07 Virulent Strain Controls Interferon Beta Production through the cGAS-STING Pathway
African Swine Fever Virus Armenia/07 Virulent Strain Controls Interferon Beta Production through the cGAS-STING Pathway
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DOI：
10.1128/jvi.02298-18
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发表时间：
2019-06-01
影响因子：
5.4
通讯作者：
Revilla, Yolanda
中科院分区：
文献类型：
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作者：
Garcia-Belmonte, Raquel;Perez-Nunez, Daniel;Revilla, Yolanda
非洲猪瘟病毒(ASFV)是一种复杂的细胞质双链DNA(DsDNA)病毒，目前正在世界各地蔓延。目前，流行的强毒基因II亚美尼亚/07类病毒会在猪和野猪中引起致命疾病，而减毒株则会导致不同程度的慢性病感染。细胞内dsDNA的感测主要通过DNA传感器环状GMP-AMP合成酶(CGAS)来实现，导致I型干扰素的合成，并通过STINT、TBK1和IRF3进行信号传递。在磷酸化后，STING从内质网转移到高尔基体和核周区域，作为连接胞浆DNA检测和TBK1-IRF3信号通路的不可或缺的适配器。我们在这里证明了减毒的NH/P68，但不是毒力的亚美尼亚/07，在感染过程中很早就激活了cGAS-STING-IRF3级联，通过涉及cGAMP的机制诱导STING磷酸化和运输。随后，TBK1和IRF3都被激活，作为回应，在NH/P68感染期间产生了高水平的β干扰素(干扰素-β)；相比之下，亚美尼亚/07感染产生的干扰素-β水平低于未感染细胞。我们的结果表明，强毒亚美尼亚/07 ASFV控制cGAS刺痛途径，但当猪巨噬细胞感染减毒NH/P68 ASFV时，这些机制不起作用。这些发现首次表明cGAS-STING-IRF3途径参与了ASFV感染，在ASFV弱毒株和强毒株感染后，分别发现干扰素-β的产生或抑制，从而强化了ASFV毒力与减弱可能是基于ASFV介导的先天性免疫调节的现象，其中cGAS-STING途径可能发挥重要作用。非洲猪瘟是一种对家猪和野猪具有破坏性的疾病，目前正在欧洲、俄罗斯和中国蔓延，成为具有巨大经济和生态后果的全球威胁。ASFV生物学的一个有趣的方面是，与产生亚临床感染的更弱的菌株相比，一些菌株的分子机制导致了高毒力。在这项工作中，我们证明了目前流行的强毒亚美尼亚/07病毒阻止了干扰素-β的合成，干扰素-β是先天免疫反应和获得性免疫反应之间的关键中介。亚美尼亚/07通过削弱感染期间的刺痛激活来抑制cGAS-刺痛途径。相反，在NH/P68减毒株感染期间，cGAS-STING途径被有效激活，导致大量干扰素-β的产生。我们的结果首次揭示了cGAS-STING途径与ASFV毒力之间的关系，有助于揭示ASFV毒力的分子机制，并有助于ASFV疫苗的合理开发。
African swine fever virus (ASFV) is a complex, cytoplasmic double-stranded DNA (dsDNA) virus that is currently expanding throughout the world. Currently, circulating virulent genotype II Armenia/07-like viruses cause fatal disease in pigs and wild boar, whereas attenuated strains induce infections with various levels of chronic illness. Sensing cytosolic dsDNA, mainly by the key DNA sensor cyclic GMP-AMP synthase (cGAS), leads to the synthesis of type I interferon and involves signaling through STING, TBK1, and IRF3. After phosphorylation, STING translocates from the endoplasmic reticulum to the Golgi compartment and to the perinuclear region, acting as an indispensable adaptor connecting the cytosolic detection of DNA to the TBK1-IRF3 signaling pathway. We demonstrate here that attenuated NH/P68, but not virulent Armenia/07, activates the cGAS-STING-IRF3 cascade very early during infection, inducing STING phosphorylation and trafficking through a mechanism involving cGAMP. Both TBK1 and IRF3 are subsequently activated and, in response to this, a high level of beta interferon (IFN-beta) was produced during NH/P68 infection; in contrast, Armenia/07 infection generated IFN-beta levels below those of uninfected cells. Our results show that virulent Armenia/07 ASFV controls the cGAS-STING pathway, but these mechanisms are not at play when porcine macrophages are infected with attenuated NH/P68 ASFV. These findings show for the first time the involvement of the cGAS-STING-IRF3 route in ASFV infection, where IFN-beta production or inhibition was found after infection by attenuated or virulent ASFV strains, respectively, thus reinforcing the idea that ASFV virulence versus attenuation may be a phenomenon grounded in ASFV-mediated innate immune modulation where the cGAS-STING pathway might play an important role.IMPORTANCE African swine fever, a devastating disease for domestic pigs and wild boar, is currently spreading in Europe, Russia, and China, becoming a global threat with huge economic and ecological consequences. One interesting aspect of ASFV biology is the molecular mechanism leading to high virulence of some strains compared to more attenuated strains, which produce subclinical infections. In this work, we show that the presently circulating virulent Armenia/07 virus blocks the synthesis of IFN-beta, a key mediator between the innate and adaptive immune response. Armenia/07 inhibits the cGAS-STING pathway by impairing STING activation during infection. In contrast, the cGAS-STING pathway is efficiently activated during NH/P68 attenuated strain infection, leading to the production of large amounts of IFN-beta. Our results show for the first time the relationship between the cGAS-STING pathway and ASFV virulence, contributing to uncover the molecular mechanisms of ASFV virulence and to the rational development of ASFV vaccines.