The Host Specificities of Baculovirus per os Infectivity Factors.
The Host Specificities of Baculovirus per os Infectivity Factors.
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杆状病毒经口感染因素的宿主特异性
DOI：
10.1371/journal.pone.0159862
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Wang M
中科院分区：
文献类型：
--
作者：
Song J;Wang X;Hou D;Huang H;Liu X;Deng F;Wang H;Arif BM;Hu Z;Wang M
杆状病毒是昆虫特异性病原体，具有通常狭窄的宿主范围。成功的原发感染是由至少8个保守的经口感染因子（PIF）与宿主中肠细胞的适当相互作用启动的，这一过程在很大程度上仍然是一个谜。本研究以棉铃虫核型多角体病毒（Helicoverpaarmigeranucleopolyhedrovirus，HearNPV）为研究对象，研究了PIF复合物的4个核心组分P74、PIF1、PIF2和PIF3的宿主特异性。HearNPV的四个pif被来自I组苜蓿银纹夜蛾多核型多角体病毒（AcMNPV）或II组斜纹夜蛾核型多角体病毒（SpltNPV）的对应物替换。转染和感染试验表明，所有重组病毒均能产生具有感染性的芽殖病毒（BV），并对H.通过血体腔内注射获得棉铃虫幼虫。然而，使用非常高浓度的包合体的饲养实验表明，除了SpltNPV pif3取代pif3-null HearNPV（vHaBac Δ pif3-Sppif3-ph）之外，所有重组病毒都完全丧失了口服感染性。生物测定结果表明，vHaBac Δ pif3-Sppif3-ph的半数致死浓度（LC50）是对照病毒vHaBac Δ pif3-Hapif3-ph的23倍，说明SpltNPV pif3只能部分替代HearNPV pif3的功能。这些结果表明，大多数测试的PIF具有严格的宿主特异性，这可能至少部分地解释了杆状病毒有限的宿主范围。
Baculoviruses are insect-specific pathogens with a generally narrow host ranges. Successful primary infection is initiated by the proper interaction of at least 8 conserved per os infectivity factors (PIFs) with the host’s midgut cells, a process that remains largely a mystery. In this study, we investigated the host specificities of the four core components of the PIF complex, P74, PIF1, PIF2 and PIF3 by using Helicoverpa armigera nucleopolyhedrovirus (HearNPV) backbone. The four pifs of HearNPV were replaced by their counterparts from a group I Autographa californica multiple nucleopolyhedrovirus (AcMNPV) or a group II Spodoptera litura nucleopolyhedrovirus (SpltNPV). Transfection and infection assays showed that all the recombinant viruses were able to produce infectious budded viruses (BVs) and were lethal to H. armigera larvae via intrahaemocoelic injection. However, feeding experiments using very high concentration of occlusion bodies demonstrated that all the recombinant viruses completely lost oral infectivity except SpltNPV pif3 substituted pif3-null HearNPV (vHaBacΔpif3-Sppif3-ph). Furthermore, bioassay result showed that the median lethal concentration (LC50) value of vHaBacΔpif3-Sppif3-ph was 23-fold higher than that of the control virus vHaBacΔpif3-Hapif3-ph, indicating that SpltNPV pif3 can only partially substitute the function of HearNPV pif3. These results suggested that most of PIFs tested have strict host specificities, which may account, at least in part, for the limited host ranges of baculoviruses.