| Super-resolution Imaging of the T cell Central Supramolecular Signaling Cluster Using Stimulated Emission Depletion Microscopy
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Author:
Date:
2020-11-05
[Abstract] Supramolecular signaling assemblies are of interest for their unique signaling properties. A µm scale signaling assembly, the central supramolecular signaling cluster (cSMAC), forms at the center interface of T cells activated by antigen presenting cells (APC). The adaptor protein linker for activation of T cells (LAT) is a key cSMAC component. The cSMAC has widely been studied using total internal reflection fluorescence microscopy of CD4+ T cells activated by planar APC substitutes. Here we provide a protocol to image the cSMAC in its cellular context at the interface between a T cell and an APC. Super resolution stimulated emission depletion microscopy (STED) was utilized to determine the localization of LAT, that of its active, phosphorylated form and its entire pool. Agonist ...
[摘要] [摘要]超分子信号组装体因其独特的信号传导特性而受到关注。在抗原呈递细胞（APC）激活的T细胞的中心界面处形成一个微米级的信号传导组件，即中央超分子信号簇（cSMAC ）。用于激活T细胞（LAT）的衔接子蛋白接头是关键的cSMAC组件。所述CSMAC已被广泛使用的CD4全内反射荧光显微镜研究+由平面APC替代活化的T细胞。在这里，我们提供了一种协议，可以在T细胞和APC之间的接口在其细胞上下文中成像cSMAC 。超分辨率激发发射耗尽显微镜（STED）用于确定LA T的定位，其活性，磷酸化形式及其整个池的位置。在固定和抗体染色之前，将载有激动剂肽的APC与TCR转基因CD4 + T细胞孵育4.5分钟。固定的细胞对在Leica SP8 AOBS共聚焦激光扫描显微镜上使用100x 1.4 NA物镜成像。LAT聚集在多个超分子复合物中，并确定了它们的数量和大小分布。使用此协议，可以量化在T细胞和APC之间的界面在其细胞环境中的cSMAC属性。
[背景] ...
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| Isolation and High Throughput Flow Cytometric Apoptosis Assay of Human Neutrophils to Enable Compound Library Screening
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Author:
Date:
2020-06-05
[Abstract] The study of human neutrophils in vitro is challenging due to their short half-life and propensity for activation. However, with careful handling and manipulation in the laboratory, they can be a powerful tool to investigate immune responses in health and disease. Here we describe a method for the isolation of human neutrophils from peripheral blood samples, followed by a high-throughput screen to assess the efficacy of a library of compounds in inducing neutrophil apoptosis, which may have therapeutic potential in neutrophil-driven diseases. This protocol is based on previously-published neutrophil isolation methods utilizing Dextran sedimentation of red blood cells followed by the separation of granulocytes with plasma/Percoll discontinuous gradient centrifugation. Yields of ~1 ...
[摘要] [摘要] 人类嗜中性粒细胞的研究 由于其半衰期短且易于活化，因此体外具有挑战性，然而，通过在实验室中的仔细处理和操纵，它们可以成为研究健康和疾病中免疫反应的有力工具。在此，我们介绍了一种分离方法外周血样本中的人类嗜中性粒细胞，然后进行高通量筛选，以评估化合物库诱导嗜中性粒细胞凋亡的功效，该化合物在嗜中性粒细胞驱动的疾病中可能具有治疗潜力。此规程基于先前发表的嗜中性粒细胞分离方法利用红细胞的葡聚糖沉降，接着用等离子体/粒细胞的分离的Percoll 〜1×10个的不连续梯度centrifugation.Yields 6 每嗜中性粒细胞毫升的血液，和>的纯度95个％嗜中性粒细胞是典型的。嗜中性粒细胞与经处理的激酶抑制剂文库，然后通过流式细胞仪评估中性粒细胞凋亡的速率。低通量用于高通量筛选人类原代免疫细胞，以鉴定具有修饰嗜中性粒细胞功能的化合物，并可根据需要进行修饰以评估其他表型。
[背景] 中性粒细胞是重要的先天免疫细胞与键的角色防御抵抗infection.They是短暂的细胞中，在感染和inflammat部位延长6-8小时循环典型的半衰期离子（萨默斯等人。 。，2010 ; Hidalgo。Et Al ...
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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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