| HCV Reporter System (Viral Infection-Activated Split-Intein-Mediated Reporter System) for Testing Virus Cell-to-cell Transmission ex-vivo
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Author:
Date:
2018-08-05
[Abstract] Hepatitis C virus (HCV) spread involves two distinct entry pathways: cell-free transmission and cell-to-cell transmission. Cell-to-cell transmission is not only an efficient way for viruses to spread but also an effective method for escaping neutralizing antibodies. We adapted the viral infection-activated split-intein-mediated reporter system (VISI) and developed a straightforward model for Live-cell monitoring of HCV cell-to-cell transmission ex-vivo: co-culture of HCV infected donor cells (red signal) with uninfected recipient cells (green signal) and elimination of the cell-free transmission by adding potent neutralizing antibody AR3A in the supernatant. With this model, the efficiency of cell-to-cell transmission can be evaluated by counting the number of foci designated by ...
[摘要] 丙型肝炎病毒（HCV）传播涉及两种不同的进入途径：无细胞传播和细胞间传播。 细胞间传播不仅是病毒传播的有效方式，也是逃避中和抗体的有效方法。 我们采用了病毒感染激活的分裂 - 内含肽介导的报告系统（VISI），并开发了一种直接模型，用于活细胞监测HCV细胞间传递离体：共培养 HCV感染的供体细胞（红色信号）与未感染的受体细胞（绿色信号）和通过在上清液中加入有效的中和抗体AR3A消除无细胞的传递。 利用该模型，可以通过计数受体细胞的绿色信号指定的病灶数来评估细胞间传递的效率。
【背景】越来越多的证据证明病毒可以在受感染的组织中使用不同的传播途径（Sattentau，2008; Zhong et al。，2013）。对于HCV传播，无细胞传播和细胞间传播均可介导肝细胞之间的病毒转移。虽然无细胞传播引发HCV感染，但认为细胞 - 细胞传递直接将HCV转移至相邻的肝细胞。它提供了抵抗中和抗体并有助于病毒持久性的极好方法（Brimacombe et al。，2011; Xiao et al。，2014）。之前的文章也证明了一些促进细胞传递的宿主因子，如清道夫受体BI（SR-BI），CD81，紧密连接蛋白claudin-1（CLDN1），Occludin（OCLN），表皮生长因子受体（EGFR）。 （Witteveldt et al。，2009; ...
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| Screening for Novel Endogenous Inflammatory Stimuli Using the Secreted Embryonic Alkaline Phosphatase NF-κB Reporter Assay
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Author:
Date:
2017-04-05
[Abstract] An immune response can be activated by pathogenic stimuli, as well as endogenous danger signals, triggering the activation of pattern recognition receptors and initiating signalling cascades that lead to inflammation. This method uses THP1-BlueTM cells, a human monocytic cell line which contains an embryonic alkaline phosphatase reporter gene allowing the detection of NF-κB-induced transcriptional activation. We validated this protocol by assessing NF-κB activation after stimulation of toll-like receptor 4 (TLR4) by two different agonists: lipopolysaccharide (LPS), derived from the cell wall of Gram negative bacteria, and tenascin-C, an extracellular matrix protein whose expression is induced upon tissue injury. We then used this protocol to screen for potential new endogenous ...
[摘要] 免疫反应可以被致病性刺激以及内源性危险信号激活，引发模式识别受体的激活并引发导致炎症的信号级联。该方法使用THP1-Blue TM 细胞，其是含有能够检测NF-κB诱导的转录激活的胚胎碱性磷酸酶报告基因的人单核细胞系。通过两种不同的激动剂刺激toll样受体4（TLR4）后，通过评估NF-κB活化来验证该方案：从革兰氏阴性细菌的细胞壁衍生的脂多糖（LPS）和腱生蛋白C，细胞外基质蛋白其组织损伤引起其表达。然后我们使用该方案筛选潜在的新的内源性TLR4激动剂，但是该方法也可以用作快速，经济和可靠的方法来测定导致TLR依赖性NF-κB活化的其它炎性刺激的活性。
免疫系统已经发展成不仅识别病原性刺激物，例如细菌成分和病毒核酸，还包括内源性危险信号，包括从坏死细胞分泌的蛋白质或表达于组织损伤。通过模式识别受体感测到两种类型的刺激，启动触发炎症反应的信号级联。活化的B细胞（NF-κB）的核因子κ-轻链增强子是激活对感染和组织损伤的免疫应答所必需的转录因子。 NF-κB在模式识别受体激活后，在广泛的炎症介质的表达中具有重要作用，包括细胞因子（如肿瘤坏死因子α[TNFα]，白细胞介素-6和白细胞介素-1），趋化因子例如白细胞介素-8或CXCL1），蛋白酶，生长因子和MHC相关分子等。为了评估在TLR4下游的该途径的活化，我们使用市售的细胞系THP1-Blue ...
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| Purification of HCV-remodeled and Control ER Membranes
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Author:
Date:
2014-05-20
[Abstract] As for all positive strand RNA viruses, hepatitis C virus (HCV) RNA replication is tightly associated with rearranged host cell membranes, termed viral replication factories. However, up to now little is known about both viral and cellular constituents of viral replication factories. Here, we describe a protocol to specifically isolate HCV-remodeled host cell membranes and endoplasmic reticulum (ER) membranes of naïve cells, by using a functional NS4B HA-tagged subgenomic replicon and a C-terminally HA-tagged calnexin-overexpressing cell line, respectively. Post-nuclear whole cell membrane fractions are first enriched by density gradient centrifugation, followed by HA-specific affinity tag purification. Upon elution under native conditions, purified samples can be subject to a variety of ...
[摘要] 至于所有正链RNA病毒，丙型肝炎病毒（HCV）RNA复制与称为病毒复制工厂的重排宿主细胞膜紧密相关。 然而，到目前为止对病毒复制工厂的病毒和细胞成分了解甚少。 在这里，我们描述一个协议，通过使用功能NS4B HA标记亚基因组复制子和C末端HA标记calnexin过表达细胞系，特异性隔离HCV重塑的宿主细胞膜和内质网（ER）膜的幼稚细胞， 分别。 首先通过密度梯度离心富集核后全细胞膜级分，随后通过HA特异性亲和标签纯化。 在天然条件下洗脱时，纯化的样品可进行多种生物化学和功能测定。
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