Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus
Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus
复制标题
小干扰RNA途径调节昆虫摄入病毒后中肠上皮的初始病毒感染
DOI：
10.1128/jvi.01835-15
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发表时间：
2016-01-01
影响因子：
5.4
通讯作者：
Wei, Taiyun
中科院分区：
文献类型：
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作者：
Lan, Hanhong;Chen, Hongyan;Wei, Taiyun
许多病毒通过昆虫媒介持续传播。持久性病毒在中肠上皮中建立其初始感染，从中它们传播到中肠内脏肌肉。尽管昆虫载体中病毒的传播可以通过小干扰RNA（siRNA）抗病毒途径来控制，但siRNA途径是否可以控制病毒从中肠上皮的传播尚不清楚。水稻病毒（南方水稻黑条矮缩病毒[SRBSDV]）对其无能载体（小褐飞虱[SBPH]）的感染仅限于中肠上皮。在这里，我们表明，siRNA途径是由SRBSDV感染连续培养的细胞来源于SBPH和完整的昆虫中肠。通过RNA干扰敲低siRNA途径的核心组分Dicer-2的表达，强烈增加了SRBSDV在连续培养的SBPH细胞和中肠上皮中繁殖的能力，使中肠上皮中的病毒滴度达到病毒传播到SBPH中肠肌肉中所需的阈值（1.99 × 10（9）拷贝的SRBSDV P10基因/μ g中肠RNA）。因此，我们的研究结果代表了第一次阐明的阈值从昆虫中肠上皮病毒传播。Dicer-2基因的沉默进一步促进了SRBSDV通过SBPH向水稻植株的传播。综上所述，我们的研究结果揭示了新的发现，siRNA途径可以控制病毒对昆虫中肠上皮细胞的初始感染，最终影响病毒载体的能力。重要的是，导致重大全球健康和农业问题的任何病毒病原体都是通过昆虫载体传播的。病毒感染的第一个瓶颈，中肠上皮，是昆虫物种传播病毒能力的主要决定因素。南方水稻黑条矮缩病毒（SRBSDV）仅限于一个无能的载体，小褐飞虱（SBPH）的中肠上皮。在这里，我们表明，沉默小干扰RNA（siRNA）途径的核心成分Dicer-2增加了中肠上皮细胞中的病毒滴度，超过了病毒传播到中肠肌肉中，然后进入唾液腺的阈值（1.99 × 10（9）拷贝的SRBSDV P10基因/μ g中肠RNA），使SBPH成为SRBSDV的有效载体。这一结果首次证明siRNA抗病毒途径在控制病毒从中肠上皮传播中具有直接作用，并且影响病毒载体的能力。
Numerous viruses are transmitted in a persistent manner by insect vectors. Persistent viruses establish their initial infection in the midgut epithelium, from where they disseminate to the midgut visceral muscles. Although propagation of viruses in insect vectors can be controlled by the small interfering RNA (siRNA) antiviral pathway, whether the siRNA pathway can control viral dissemination from the midgut epithelium is unknown. Infection by a rice virus (Southern rice black streaked dwarf virus [SRBSDV]) of its incompetent vector (the small brown planthopper [SBPH]) is restricted to the midgut epithelium. Here, we show that the siRNA pathway is triggered by SRBSDV infection in continuously cultured cells derived from the SBPH and in the midgut of the intact insect. Knockdown of the expression of the core component Dicer-2 of the siRNA pathway by RNA interference strongly increased the ability of SRBSDV to propagate in continuously cultured SBPH cells and in the midgut epithelium, allowing viral titers in the midgut epithelium to reach the threshold (1.99 x 10(9) copies of the SRBSDV P10 gene/mu g of midgut RNA) needed for viral dissemination into the SBPH midgut muscles. Our results thus represent the first elucidation of the threshold for viral dissemination from the insect midgut epithelium. Silencing of Dicer-2 further facilitated the transmission of SRBSDV into rice plants by SBPHs. Taken together, our results reveal the new finding that the siRNA pathway can control the initial infection of the insect midgut epithelium by a virus, which finally affects the competence of the virus's vector.IMPORTANCEMany viral pathogens that cause significant global health and agricultural problems are transmitted via insect vectors. The first bottleneck in viral infection, the midgut epithelium, is a principal determinant of the ability of an insect species to transmit a virus. Southern rice black streaked dwarf virus (SRBSDV) is restricted exclusively to the midgut epithelium of an incompetent vector, the small brown planthopper (SBPH). Here, we show that silencing of the core component Dicer-2 of the small interfering RNA (siRNA) pathway increases viral titers in the midgut epithelium past the threshold (1.99 x 10(9) copies of the SRBSDV P10 gene/mu g of midgut RNA) for viral dissemination into the midgut muscles and then into the salivary glands, allowing the SBPH to become a competent vector of SRBSDV. This result is the first evidence that the siRNA antiviral pathway has a direct role in the control of viral dissemination from the midgut epithelium and that it affects the competence of the virus's vector.