| Imaging Cytokine Concentration Fields Using PlaneView Imaging Devices
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Author:
Date:
2018-04-05
[Abstract] We describe here a method to visualize concentration fields of cytokines around cytokine-secreting cells. The main challenge is that physiological cytokine concentrations can be very low, in the pico-molar range. Since it is currently impossible to measure such concentrations directly, we rely on cell’s response to the cytokines–the phosphorylation of a transcription factor–that can be visualized through antibody staining. Our devices aim at mimicking conditions in dense tissues, such as lymph nodes. A small number of secreting cells is deposited on a polylysine-coated glass and covered by multiple layers of cytokine-consuming. The cells are left to communicate for 1 h, after which the top layers are removed and the bottom layer of cells is antibody labeled for the response to cytokines. ...
[摘要] 我们在这里描述了一种可视化细胞因子分泌细胞周围细胞因子浓度场的方法。主要挑战是生理细胞因子浓度可能非常低，在微摩尔浓度范围内。由于目前不可能直接测量这样的浓度，我们依赖于细胞对细胞因子的反应 - 转录因子的磷酸化 - 可以通过抗体染色显现。我们的设备旨在模仿密集组织中的条件，如淋巴结。少数分泌细胞沉积在聚赖氨酸包被的玻璃上并被多层细胞因子消耗覆盖。将细胞连通1小时，之后去除顶层，并且细胞的底层被抗体标记为对细胞因子的应答。然后通过标准荧光显微镜观察细胞因子场的横截面。这篇手稿总结了我们的方法，以量化密集细胞体外细胞因子介导的细胞间通讯的程度。
【背景】哺乳动物的免疫系统已经发展到能够识别和限制潜在病原体的传播，同时使由免疫系统本身造成的附带组织损伤最小化。为了实现这一点，免疫细胞依赖细胞因子介质网络，这些细胞因子介质能够进行细胞间通讯并广播关于致病性侮辱的大小和性质的信息。大量不同细胞因子与其同源受体强烈结合，通常在纳摩尔或皮摩尔范围内具有特征性结合亲和力。通过细胞因子通讯产生免疫龛。例如，在骨髓和胸腺中，通过基质细胞分泌的白细胞介素-7（IL-7）分别支持增殖的B细胞和T细胞祖细胞的存活（Tokoyoda et al。， 2004; Alves等人，2009）。细胞因子生态位的大小控制成熟祖细胞的数量，从而保持血细胞区室平衡（Böyum，1968; ...
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| Active Cdk5 Immunoprecipitation and Kinase Assay
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Author:
Date:
2017-07-05
[Abstract] Cdk5 activity is regulated by the amounts of two activator proteins, p35 and p39 (Tsai et al., 1994; Zheng et al., 1998; Humbert et al., 2000). The p35-Cdk5 and p39-Cdk5 complexes have differing sensitivity to salt and detergent concentrations (Hisanaga and Saito, 2003; Sato et al., 2007; Yamada et al., 2007; Asada et al., 2008). Cdk5 activation can be directly measured by immunoprecipitation of Cdk5 with its bound activator, followed by a Cdk5 kinase assay. In this protocol, buffers for cell lysis and immunoprecipitation are intended to preserve both p35- and p39-Cdk5 complexes to assess total Cdk5 activity. Cells are lysed and protein concentration is determined in the post-nuclear supernatant. Cdk5 is immunoprecipitated from equal ...
[摘要] Cdk5活性受两种激活蛋白p35和p39（Tsai et al。，1994; Zheng et al。，1998; Humbert等人）的量的调节，2000）。 p35-Cdk5和p39-Cdk5复合物对盐和洗涤剂浓度的敏感性不同（Hisanaga和Saito，2003; Sato et al。，2007; Yamada等人， 2007; Asada 等人，2008）。 Cdk5激活可以通过Cdk5与其结合的激活剂的免疫沉淀直接测量，随后进行Cdk5激酶测定。在该方案中，用于细胞裂解和免疫沉淀的缓冲液旨在保持p35-和p39-Cdk5复合物以评估总Cdk5活性。裂解细胞，并在核后上清液中测定蛋白浓度。 Cdk5在实验组之间从等量的总蛋白免疫沉淀。然后进行洗涤以除去外来蛋白质并平衡激酶缓冲液中的Cdk5-活化剂复合物。然后将Cdk5与组蛋白H1孵育，组蛋白H1是Cdk5和[γ- 32 P] ATP在体外成功建立的靶标。反应通过SDS-PAGE解析并转移到膜上，用于可视化H1磷酸化和免疫沉淀的Cdk5水平的免疫印迹。我们已经使用该测定来建立p39作为少突神经胶质谱系中Cdk5的主要活化剂。然而，该测定法适用于对裂解条件进行适当调整的其它细胞谱系或组织。
【背景】虽然Cdk5通常与神经元功能相关，但最近的工作已经证明Cdk5也可以调节少突胶质细胞祖细胞（OPC）的发育（Tang等人，1998; ...
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| Imaging Thick Lymph Node Tissue Sections
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Author:
Date:
2016-09-20
[Abstract] Our protocol describes a simple procedure for imaging thick lymph node sections by 2-photon microscopy. Lymph nodes are sectioned using a vibratome (vibrating microtome) to produce slices of tissue that can then be stained with fluorescently labeled antibodies. The thick tissue sections (150-200 μm depth) allow for the detection of cell clustering that is typically under-represented in thin sections (10-20 μm) used for conventional confocal microscopy. Application of 2-photon microscopy facilitates imaging through the thick volume of the vibratome sections. In combination with automated image processing software, a thick lymph node cross-section image also facilitates quantitation of cellular events within a relatively large area of the tissue, thus providing a clearer picture on the ...
[摘要] 我们的协议描述了一个简单的程序，通过双光子显微镜成像厚淋巴结切片。 使用vibratome（振动切片机）切割淋巴结以产生组织切片，然后可用荧光标记的抗体染色。 厚组织切片（150-200μm深度）允许检测细胞聚集，其通常在用于常规共聚焦显微镜的薄切片（10-20μm）中表现不足。 双光子显微镜的应用有利于成像通过厚的体积的vibratome部分。 与自动图像处理软件组合，厚的淋巴结横截面图像还有助于在组织的相对大的区域内的细胞事件的定量，从而提供关于感兴趣的细胞事件的空间分布的更清晰的图像（例如 。，T细胞聚类）。 该方法也可以容易地应用于其它组织，例如脾或皮肤。
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