Imd pathway-specific immune assays reveal NF-κB stimulation by viral RNA PAMPs in Aedes aegypti Aag2 cells.
Imd pathway-specific immune assays reveal NF-κB stimulation by viral RNA PAMPs in Aedes aegypti Aag2 cells.
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Imd途径特异性免疫分析揭示了埃及伊蚊Aag 2细胞中病毒RNA PAMP对NF-κB的刺激作用。
DOI：
10.1371/journal.pntd.0008524
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发表时间：
2021-03
影响因子：
3.8
通讯作者：
Maringer K
中科院分区：
文献类型：
--
作者：
Russell TA;Ayaz A;Davidson AD;Fernandez-Sesma A;Maringer K
埃及伊蚊是节肢动物传播的基孔肯雅病毒、登革热、黄热病和寨卡病毒的主要媒介。媒介免疫反应是虫媒病毒传播的主要障碍，已经提出将具有改变的免疫力的转基因昆虫作为减少虫媒病毒疾病对全球公共卫生影响的工具。然而，需要更好地了解病毒-免疫相互作用以促进此类转基因昆虫的发展。虽然NF-κ B调节的Toll和“免疫缺陷”（Imd）途径越来越被认为是抗病毒的，但相关的模式识别受体（PRR）和病原体相关的分子模式（PAMP）在A.埃及人。我们开发了新的RT-qPCR和荧光素酶报告基因测定法来测量常用的A.埃及伊蚊Aag 2细胞系。因此，我们确定Toll途径在我们的实验条件下在Aag 2细胞中不能通过细菌、病毒或真菌刺激物的外源刺激诱导。我们使用我们的Imd途径特异性测定来证明病毒dsRNA模拟物poly（I：C）被Imd途径感测，可能通过细胞内和细胞外PRR。Imd途径也在用模型昆虫特异性病毒蟋蟀麻痹病毒（CrPV）感染期间诱导。我们证明，许多虫媒病毒共享的一般PAMP是由Imd途径感知的，这为未来的研究铺平了道路，以确定病毒RNA如何在分子水平上被蚊子PRR感知。我们的数据还表明，由于Toll途径在所有实验条件下均无反应，因此应谨慎解释通过Aag 2细胞中抗菌肽（AMP）表达测量诱导型免疫途径活化的研究。由于没有抗病毒疗法，也没有有效的疫苗可用于治疗虫媒病毒疾病，我们的研究结果为转基因蚊子的发展提供了新的见解，作为减少虫媒病毒传播的一种手段。埃及伊蚊在全球热带和亚热带地区发现，传播对全球公共卫生产生重大影响的病毒，包括基孔肯雅病毒、登革热、黄热病和寨卡病毒。目前还没有抗病毒药物来治疗这些疾病，也没有有效的疫苗。减少蚊子传播疾病的全球负担的一种方法是开发不能传播病毒的转基因蚊子。一种方法是改变蚊子的免疫系统，使它们能够更好地对抗病毒感染。要做到这一点，我们首先需要了解蚊子免疫系统是如何检测病毒的。我们开发了测量实验室培养的蚊子细胞中免疫反应的新方法，并使用它们来证明免疫系统的一个特定分支，称为“Imd途径”，可以检测构成蚊子传播病毒基因组的RNA。这些发现为未来的免疫研究铺平了道路，这些研究可以为无传播能力的蚊子的发展提供信息。我们还发现，免疫系统的另一个分支，称为“Toll途径”，在本研究中使用的任何实验条件下都不起作用。这一发现对不同实验室如何解释这些特定培养细胞的数据具有影响。
The mosquito Aedes aegypti is a major vector for the arthropod-borne viruses (arboviruses) chikungunya, dengue, yellow fever and Zika viruses. Vector immune responses pose a major barrier to arboviral transmission, and transgenic insects with altered immunity have been proposed as tools for reducing the global public health impact of arboviral diseases. However, a better understanding of virus-immune interactions is needed to progress the development of such transgenic insects. Although the NF-κB-regulated Toll and ‘immunodeficiency’ (Imd) pathways are increasingly thought to be antiviral, relevant pattern recognition receptors (PRRs) and pathogen-associated molecular patterns (PAMPs) remain poorly characterised in A. aegypti. We developed novel RT-qPCR and luciferase reporter assays to measure induction of the Toll and Imd pathways in the commonly used A. aegypti-derived Aag2 cell line. We thus determined that the Toll pathway is not inducible by exogenous stimulation with bacterial, viral or fungal stimuli in Aag2 cells under our experimental conditions. We used our Imd pathway-specific assays to demonstrate that the viral dsRNA mimic poly(I:C) is sensed by the Imd pathway, likely through intracellular and extracellular PRRs. The Imd pathway was also induced during infection with the model insect-specific virus cricket paralysis virus (CrPV). Our demonstration that a general PAMP shared by many arboviruses is sensed by the Imd pathway paves the way for future studies to determine how viral RNA is sensed by mosquito PRRs at a molecular level. Our data also suggest that studies measuring inducible immune pathway activation through antimicrobial peptide (AMP) expression in Aag2 cells should be interpreted cautiously given that the Toll pathway is not responsive under all experimental conditions. With no antiviral therapies and few effective vaccines available to treat arboviral diseases, our findings provide new insights relevant to the development of transgenic mosquitoes as a means of reducing arbovirus transmission. The mosquito Aedes aegypti, found globally across the tropics and subtropics, transmits viruses with a significant global public health impact, including chikungunya, dengue, yellow fever and Zika viruses. There are no antiviral drugs to treat these diseases and few effective vaccines. One way of reducing the global burden of mosquito-borne diseases would be to develop genetically modified mosquitoes unable to transmit viruses. One approach would be to alter the mosquitoes’ immune system to allow them to better fight viral infections. To do so, we first need to understand how viruses are detected by the mosquito immune system. We developed new methods of measuring immune responses in laboratory-cultured mosquito cells and used them to show that one specific arm of the immune system, called the ‘Imd pathway’, can detect the RNA that constitutes the genome of mosquito-borne viruses. These findings pave the way for future immune studies that could inform the development of transmission-incompetent mosquitoes. We also found that another arm of the immune system, called the ‘Toll pathway’, is not functional under any experimental conditions used in this study. This finding has implications for how different laboratories interpret data from these particular cultured cells.
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DOI：
10.1080/2159256x.2017.1362494
发表时间：
2017
期刊：
Mobile genetic elements
影响因子：
--
作者：
Davidson AD;Matthews DA;Maringer K
通讯作者：
Maringer K
激酶IKKβ调节果蝇中的STING和NF-κB依赖性抗病毒反应途径。
影响因子：
32.4
作者：
Goto A;Okado K;Martins N;Cai H;Barbier V;Lamiable O;Troxler L;Santiago E;Kuhn L;Paik D;Silverman N;Holleufer A;Hartmann R;Liu J;Peng T;Hoffmann JA;Meignin C;Daeffler L;Imler JL
通讯作者：
Imler JL
蛋白质组学通过转录组学告知，以表征伊蚊中的主动转座元件和基因组注释。
影响因子：
4.4
作者：
Maringer K;Yousuf A;Heesom KJ;Fan J;Lee D;Fernandez-Sesma A;Bessant C;Matthews DA;Davidson AD
通讯作者：
Davidson AD
影响因子：
4.8
作者：
Hedengren-Olcott, M;Olcott, MC;Taylor, BJ
通讯作者：
Taylor, BJ
影响因子：
3.8
作者：
Asad, Sultan;Parry, Rhys;Asgari, Sassan
通讯作者：
Asgari, Sassan