| DNA Damage Induction by Laser Microirradiation
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Author:
Date:
2016-12-05
[Abstract] Genome instability can lead to cell death, senescence and cancerous transformation. Specific repair pathways have evolved to prevent accumulation of DNA lesions. Studying these highly dynamic and specific repair pathways requires precise spatial and temporal resolution, which can be achieved through a combination of laser microirradiaiton and live cell microscopy. DNA lesions are introduced at pre-determined sub-nuclear sites and repair can be analyzed in real time in living cells when using fluorescently tagged repair proteins (Mortusewicz et al., 2008). Alternatively, laser microirradiation can be combined with immunofluorescence analysis to study recruitment of endogenous proteins to laser-induced DNA damage tracks that can be visualized by positive controls like, e.g., ...
[摘要] 基因组不稳定性可导致细胞死亡，衰老和癌性转化。特异性修复途径已经进化以防止DNA损伤的累积。研究这些高度动态和特定的修复途径需要精确的空间和时间分辨率，这可以通过激光微激光和活细胞显微镜的组合实现。当使用荧光标记的修复蛋白时，在预定的亚核位点引入DNA损伤并且可以在活细胞中实时分析修复（Mortusewicz等人，2008）。或者，激光微辐照可与免疫荧光分析结合以研究内源蛋白质对激光诱导的DNA损伤轨迹的募集，其可通过阳性对照例如标记DNA断裂位点的γH2AX显现。
关键字：微辐射，活细胞成像，DNA损伤，DNA修复，DNA损伤，DNA损伤反应，免疫荧光，显微镜等
/strong>哺乳动物细胞的基因组完整性不断受到通过外部和内部来源引入的DNA损伤的挑战。最常见的DNA损伤是氧化碱基，双链断裂，单链断裂，链间和链内交联和UV加合物。已经发展了各种DNA损伤信号传导和修复途径以处理这些损伤。为了使DNA修复快速，精确和有效，涉及感测，信号传导和修复特定DNA损伤的许多蛋白质必须在空间和时间上协调。此外，DNA被组织成更高级的染色质结构，因此对于DNA损伤，DNA修复酶是可及的，染色质必须重塑。激光微照射与高级活细胞显微镜相结合允许在活细胞的上下文中研究这些高度动态的过程（Mortusewicz等人，2008）。这里描述的协议使用405 ...
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| Analysis of Phagosomal Antigen Degradation by Flow Organellocytometry
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Author:
Date:
2016-11-20
[Abstract] Professional phagocytes internalize self and non-self particles by phagocytosis to initiate innate immune responses. After internalization, the formed phagosome matures through fusion and fission events with endosomes and lysosomes to obtain a more acidic, oxidative and hydrolytic environment for the degradation of its cargo. Interestingly, phagosome maturation kinetics differ between cell types and cell activation states. This protocol allows to quantify phagosome maturation kinetics on a single organelle level in different types of phagocytes using flow cytometry. Here, ovalbumin (OVA)-coupled particles are used as phagocytosis model system in dendritic cells (DC), which are internalized by phagocytosis. After different time points, phagosome maturation parameters, such as phagosomal ...
[摘要] 专业吞噬细胞通过吞噬作用内化自身和非自身颗粒以启动先天免疫应答。内化后，形成的吞噬体通过与内体和溶酶体的融合和裂变事件成熟，以获得更酸性，氧化和水解的环境用于其货物的降解。有趣的是，吞噬体成熟动力学在细胞类型和细胞活化状态之间不同。该协议允许使用流式细胞术定量不同类型的吞噬细胞中单个细胞器水平上的吞噬体成熟动力学。在这里，卵白蛋白（OVA）耦合的颗粒用作吞噬作用模型系统在树突状细胞（DC），其通过吞噬内化。在不同的时间点之后，吞噬体成熟参数，例如OVA的吞噬体降解和溶酶体蛋白（例如LAMP-1）的获得，可以通过流式细胞器细胞计数以高度定量的方式同时测量。这些读出可以与其他吞噬体功能相关，例如抗原降解，在DC中的加工和负载。
[背景] ...
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| HIV-1 Fusion Assay
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Author:
Date:
2014-08-20
[Abstract] The HIV-1 fusion assay measures all steps in the HIV-1 life cycle up to and including viral fusion. It relies on the incorporation of a β-lactamase–Vpr (BlaM-Vpr) protein chimera into the virion and the subsequent transfer of this chimera into the target cell by fusion (Figure 1). The transfer is monitored by the enzymatic cleavage of CCF2, a fluorescent dye substrate of β-lactamase, loaded into the target cells. Cleavage of the β-lactam ring in CCF2 by β-lactamase changes the fluorescence emission spectrum of the dye from green (520 nm) to blue (447 nm). This change reflects virion fusion and can be detected by flow cytometry (Figure 2).
[摘要] HIV-1融合测定测量HIV-1生命周期中直至并包括病毒融合的所有步骤。 它依赖于将β-内酰胺酶-Vpr（BlaM-Vpr）蛋白嵌合体并入病毒体中，并且随后通过融合将该嵌合体转移到靶细胞中（图1）。 通过CCF2（一种β-内酰胺酶的荧光染料底物）的酶裂解来监测转移，将其装载到靶细胞中。 β-内酰胺酶在CCF2中的β-内酰胺环的切割将染料的荧光发射光谱从绿色（520nm）改变为蓝色（447nm）。 这种变化反映了病毒体融合，并且可以通过流式细胞术检测（图2）。
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