Autographa californica multiple nucleopolyhedrovirus ODV-E56 envelope protein is required for oral infectivity and can be substituted functionally by Rachiplusia ou multiple nucleopolyhedrovirus ODV-E56
Autographa californica multiple nucleopolyhedrovirus ODV-E56 envelope protein is required for oral infectivity and can be substituted functionally by Rachiplusia ou multiple nucleopolyhedrovirus ODV-E56
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DOI：
10.1099/vir.0.017160-0
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发表时间：
2010-05-01
影响因子：
3.8
通讯作者：
Bonning, Bryony C.
中科院分区：
文献类型：
--
作者：
Harrison, Robert L.;Sparks, Wendy O.;Bonning, Bryony C.
苜蓿银纹夜蛾核型多角体病毒（Autographa californica multiple nucleopolyhedrovirus，AcMNPV）odv-e56基因编码一种封闭衍生病毒（occlusion derived virus，ODV）特异性包膜蛋白ODV-E56。在先前的分析中，发现odv-e56基因处于正选择压力下，这表明它可能是病毒宿主范围的决定因素。为了评估ODV-E56在口腔感染性和宿主范围中的作用，我们构建了重组AcMNPV克隆（Ac 69 GFP-e56 lacZ和AcIEGFP-e56 lacZ），其中通过将β-半乳糖苷酶（lacZ）表达盒插入到odv-e56开放阅读框架中来消除ODV-E56蛋白合成。我们还构建了一种重组病毒Ac 69 GFP-Roe 56，其中天然AcMNPV odv-e56编码序列被Rachiplusia ou multiple nucleopolyhedrovirus（RoMNPV）的编码序列取代，RoMNPV是一种密切相关的病毒，对某些宿主物种的毒性明显高于AcMNPV。odv-e56重组病毒在细胞培养中的多角体产生和形态发生或感染性出芽病毒的产生方面没有表现出改变。在生物测定中使用三个鳞翅目宿主物种，口服感染的odv-e56突变病毒Ac 69 GFP-e56 lacZ和AcIEGFP-e56 lacZ相比，野生型和控制重组病毒的严重受损。通过用AcMNPV或RoMNPV odv-e56基因对odv-e56突变病毒进行标记拯救，口腔感染性完全恢复。在使用两种对RoMNPV比AcMNPV更敏感的宿主物种的生物测定中，Ac 69 GFP-Roe 56杀死幼虫的LC（50）值与表达AcMNPV ODV-E56的重组病毒的LC（50）值相似。该结果表明，用RoMNPV直向同源物替换AcMNPV odv-e56基因不会增加对这两个物种的毒力。
The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) odv-e56 gene encodes an occlusion-derived virus (ODV)-specific envelope protein, ODV-E56. In a previous analysis, the odv-e56 gene was found to be under positive selection pressure, suggesting that it may be a determinant of virus host range. To assess the role of ODV-E56 in oral infectivity and host range, we constructed recombinant AcMNPV clones (Ac69GFP-e56lacZ and AcIEGFP-e56lacZ) in which ODV-E56 protein synthesis was eliminated by inserting a beta-galactosidase (lacZ) expression cassette into the odv-e56 open reading frame. We also constructed a recombinant virus, Ac69GFP-Roe56, in which the native AcMNPV odv-e56 coding sequence was replaced with that of Rachiplusia ou multiple nucleopolyhedrovirus (RoMNPV), a closely related virus that is significantly more virulent towards some host species than AcMNPV. The odv-e56 recombinant viruses exhibited no alterations in polyhedron production and morphogenesis or in the production of infectious budded virus in cell culture. In bioassays using three lepidopteran host species, the oral infectivities of the odv-e56 mutant viruses Ac69GFP-e56lacZ and AcIEGFP-e56lacZ were profoundly impaired compared with those of wild-type and control recombinant viruses. Oral infectivity was restored fully by marker rescue of the odv-e56 mutant viruses with either the AcMNPV or the RoMNPV odv-e56 gene. In bioassays using two host species that are more susceptible to RoMNPV than to AcMNPV, Ac69GFP-Roe56 killed larvae with LC(50) values similar to those of recombinant viruses expressing AcMNPV ODV-E56. This result indicated that replacement of the AcMNPV odv-e56 gene with the RoMNPV orthologue did not increase virulence against these two species.