Bat Severe Acute Respiratory Syndrome-Like Coronavirus WIV1 Encodes an Extra Accessory Protein, ORFX, Involved in Modulation of the Host Immune Response
Bat Severe Acute Respiratory Syndrome-Like Coronavirus WIV1 Encodes an Extra Accessory Protein, ORFX, Involved in Modulation of the Host Immune Response
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蝙蝠类严重急性呼吸系统综合症冠状病毒 WIV1 编码一种额外的辅助蛋白 ORFX，参与宿主免疫反应的调节。
DOI：
10.1128/jvi.03079-15
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发表时间：
2016-07-01
影响因子：
5.4
通讯作者：
Shi, Zheng-Li
中科院分区：
文献类型：
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作者：
Zeng, Lei-Ping;Gao, Yu-Tao;Shi, Zheng-Li
蝙蝠具有严重的急性呼吸道综合征（SARS）类冠状病毒（SL-COV），从中认为2002-2003 SARS大流行的病因是起源的。然而，尽管在蝙蝠中发现了大量遗传多样的SL-COV序列，但仅在体外成功地培养了两种菌株（命名为WIV1和WIV16）。这两种菌株与SARS-COV仅在ORF6和ORF7之间包含一个额外的开放阅读框（命名为ORFX），而与任何已知蛋白序列没有同源性。在这项研究中，我们构建了SL-COV WIV1（RWIV1），ORFX缺失突变体（RWIV1-DELTA X）和绿色荧光蛋白（GFP）表达突变体（RWIV1-GFP-DELTA X）的全长cDNA克隆。北印迹和荧光显微镜表明ORFX在WIV1感染过程中表达。病毒感染分析表明，在Vero E6，Calu-3和Hela-HACE2细胞中，RWIV1-DELTA X在RWIV1中的有效复制。 Further study showed that ORFX could inhibit interferon production and activate NF-kappa B. Our results demonstrate for the first time that the unique ORFX in the WIV1 strain is a functional gene involving modulation of the host immune response but is not essential for in vitro viral replication.IMPORTANCEBats harbor genetically diverse SARS-like coronaviruses (SL-CoVs), and some of them have the potential for interspecies transmission.在两个最近隔离的BAT SL -COV菌株（WIV1和-16）的基因组中鉴定了一个独特的开放式阅读框（ORFX）。因此，至关重要的是要阐明该蛋白在病毒感染期间是否有助于毒力。在这里，我们透露，唯一的ORFX是一种功能基因，与宿主免疫反应的调节有关，但对于体外病毒复制并不是必不可少的。我们的结果提供了重要的信息，以进一步探索ORFX功能。此外，我们构建的反向遗传学系统将有助于研究这一病毒的发病机理，并开发用于对新兴SARS样感染的未来控制的治疗学。
Bats harbor severe acute respiratory syndrome (SARS)-like coronaviruses (SL-CoVs) from which the causative agent of the 2002-2003 SARS pandemic is thought to have originated. However, despite the fact that a large number of genetically diverse SL-CoV sequences have been detected in bats, only two strains (named WIV1 and WIV16) have been successfully cultured in vitro. These two strains differ from SARS-CoV only in containing an extra open reading frame (ORF) (named ORFX), between ORF6 and ORF7, which has no homology to any known protein sequences. In this study, we constructed a full-length cDNA clone of SL-CoV WIV1 (rWIV1), an ORFX deletion mutant (rWIV1-Delta X), and a green fluorescent protein (GFP)-expressing mutant (rWIV1-GFP-Delta X). Northern blotting and fluorescence microscopy indicate that ORFX was expressed during WIV1 infection. A virus infection assay showed that rWIV1-Delta X replicated as efficiently as rWIV1 in Vero E6, Calu-3, and HeLa-hACE2 cells. Further study showed that ORFX could inhibit interferon production and activate NF-kappa B. Our results demonstrate for the first time that the unique ORFX in the WIV1 strain is a functional gene involving modulation of the host immune response but is not essential for in vitro viral replication.IMPORTANCEBats harbor genetically diverse SARS-like coronaviruses (SL-CoVs), and some of them have the potential for interspecies transmission. A unique open reading frame (ORFX) was identified in the genomes of two recently isolated bat SL-CoV strains (WIV1 and -16). It will therefore be critical to clarify whether and how this protein contributes to virulence during viral infection. Here we revealed that the unique ORFX is a functional gene that is involved in the modulation of the host immune response but is not essential for in vitro viral replication. Our results provide important information for further exploration of the ORFX function in the future. Moreover, the reverse genetics system we constructed will be helpful for study of the pathogenesis of this group of viruses and to develop therapeutics for future control of emerging SARS-like infections.