Virus-Derived DNA Forms Mediate the Persistent Infection of Tick Cells by Hazara Virus and Crimean-Congo Hemorrhagic Fever Virus.
Virus-Derived DNA Forms Mediate the Persistent Infection of Tick Cells by Hazara Virus and Crimean-Congo Hemorrhagic Fever Virus.
复制标题
病毒衍生的 DNA 形式介导哈扎拉病毒和克里米亚-刚果出血热病毒对蜱细胞的持续感染。
DOI：
10.1128/jvi.01638-21
复制
发表时间：
2021
影响因子：
5.4
通讯作者：
Salvati MV
中科院分区：
文献类型：
--
作者：
Salvati MV
克里米亚-刚果出血热（Crimean-Congo hemorrhagic fever，CCHF）是由CCHF病毒（CCHFV）引起的一种严重的人类传染病。蜱属Hyalomma是病毒的宿主，它们是在吸血过程中将病毒传播给宿主的主要媒介。我们以前已经证明CCHFV可以持续感染透明膜衍生的蜱细胞系。然而，允许在蜱中建立持续性病毒感染的机制仍然未知。哈扎拉病毒（Hazara virus，HAZV）可代替CCHFV作为BSL-2模型病毒，用于研究病毒/载体相互作用。为了研究持续感染的机制，我们建立了一个体外模型，用透明膜衍生的蜱细胞系和HAZV。正如预期的那样，HAZV，像CCHFV一样，持续感染蜱细胞而没有任何细胞病变的迹象，并且感染的细胞可以培养超过3年。最有趣的是，我们证明了HAZV感染后短病毒衍生的DNA形式（vDNA）的存在。此外，我们证明了抗逆转录病毒药物叠氮胸腺嘧啶三磷酸盐可以抑制vDNA的产生，这表明vDNA是由蜱细胞中的内源性逆转录酶活性产生的。此外，我们收集的证据表明，vDNA是连续合成的，从而下调病毒复制，以促进细胞存活。最后，在CCHFV感染的蜱细胞中也检测到vDNA。总之，vDNA合成可能是控制蜱中RNA病毒复制的一种策略，从而使其持续感染。重要提示：刚果-克里米亚出血热（CCHF）是由CCHF病毒（CCHFV）引起的一种新的蜱传病毒性疾病。CCHFV是病毒的宿主，也是病毒传播的主要媒介。在这里，我们表明，蜱细胞感染哈扎拉病毒，一种非致病性模式病毒密切相关的CCHFV，含有短病毒衍生的DNA形式（vDNAs）产生的内源性逆转录酶活性。vDNA是需要病毒RNA复制以用于其连续合成的瞬时分子。有趣的是，vDNA合成似乎与下调病毒复制和促进蜱细胞活力相关。我们还在CCHFV感染的蜱细胞中检测到vDNA，这表明它们可能代表细胞对内罗病毒感染的应答中的关键因素，并且可能代表针对RNA病毒感染的先天免疫的更一般机制。
Crimean-Congo hemorrhagic fever (CCHF) is a severe disease of humans caused by CCHF virus (CCHFV), a biosafety level (BSL)-4 pathogen. Ticks of the genusHyalommaare the viral reservoir, and they represent the main vector transmitting the virus to its hosts during blood feeding. We have previously shown that CCHFV can persistently infectHyalomma-derived tick cell lines. However, the mechanism allowing the establishment of persistent viral infections in ticks is still unknown. Hazara virus (HAZV) can be used as a BSL-2 model virus instead of CCHFV to study virus/vector interactions. To investigate the mechanism behind the establishment of a persistent infection, we developed anin vitromodel withHyalomma-derived tick cell lines and HAZV. As expected, HAZV, like CCHFV, persistently infects tick cells without any sign of cytopathic effect, and the infected cells can be cultured for more than 3 years. Most interestingly, we demonstrated the presence of short viral-derived DNA forms (vDNAs) after HAZV infection. Furthermore, we demonstrated that the antiretroviral drug azidothymine triphosphate could inhibit the production of vDNAs, suggesting that vDNAs are produced by an endogenous retrotranscriptase activity in tick cells. Moreover, we collected evidence that vDNAs are continuously synthesized, thereby downregulating viral replication to promote cell survival. Finally, vDNAs were also detected in CCHFV-infected tick cells. In conclusion, vDNA synthesis might represent a strategy to control the replication of RNA viruses in ticks allowing their persistent infection.IMPORTANCECrimean-Congo hemorrhagic fever (CCHF) is an emerging tick-borne viral disease caused by CCHF virus (CCHFV). Ticks of the genusHyalommacan be persistently infected with CCHFV representing the viral reservoir, and the main vector for viral transmission. Here we showed that tick cells infected with Hazara virus, a nonpathogenic model virus closely related to CCHFV, contained short viral-derived DNA forms (vDNAs) produced by endogenous retrotranscriptase activity. vDNAs are transitory molecules requiring viral RNA replication for their continuous synthesis. Interestingly, vDNA synthesis seemed to be correlated with downregulation of viral replication and promotion of tick cell viability. We also detected vDNAs in CCHFV-infected tick cells suggesting that they could represent a key element in the cell response to nairovirus infection and might represent a more general mechanism of innate immunity against RNA viral infection.