Bioluminescent indicators in living mammals
Bioluminescent indicators in living mammals
复制标题
DOI：
10.1038/nm0298-245
复制
发表时间：
1998-02-01
期刊：
影响因子：
82.9
通讯作者：
Contag, CH
中科院分区：
文献类型：
--
作者：
Contag, PR;Olomu, IN;Contag, CH
有许多生物过程不能通过非侵入性成像方式进行外部监测，如磁共振成像（MRI）、正电子发射断层扫描（PET）或x射线（计算机断层扫描，CT），因为这些过程中的关键分子即使在造影剂或放射性示踪剂的存在下也无法区分。具有光学特征（例如荧光、彩色或生物发光）的报告基因已被用于细胞培养、相对透明的小生物（果蝇）或二维生物（植物叶片），以及在大型动物中表达后的离体分析。在这种分析中，报告基因与遗传调控元件相关联，可以在转录水平上揭示各种生物过程的时空信息。我们的实验室最近实现了对完整的活体哺乳动物的生物事件进行实时分析的目标。两个关键的观察导致了这项技术的发展。第一个观察是，生物光源足够强，以至于哺乳动物体内产生的光可以被外部检测到。”第二个观察结果是，无论是内源性（细菌）还是外源性（昆虫）的底物，都可以在活体哺乳动物中获得生物荧光报告。我们已经使用了灵敏的检测设备，通过检测从哺乳动物组织内部传输的光子来可视化和量化生物发光。”最近，利用电荷耦合器件（CCD）相机对弱可见光源成像的若干技术进步已经出现，包括微通道板增强器、探测器的珀尔帖或液氮冷却，以及一种组合，其中增强器而不是CCD探测器被冷却。这些技术的目标是通过降低背景（冷却）或增加信号（增强）来提高信噪比。这些仪器在科学和工业中有广泛的应用，并可从各种商业来源获得。本实验室采用滨松强化CCD （ICCD，型号C2400-32）监测活体哺乳动物的感染和基因表达。
Background There are many biological processes that can not be externally monitored with noninvasive imaging modalities such as magnetic resonance imaging (MRI), positron emission tomography (PET) or via x-rays (computerized tomography, CT), because key molecules in these processes are not distinguishable even in the presence of contrast dyes or radioactive tracers. Reporter genes with optical signatures (for example, fluorescence, color or bioluminescence) have been used in cell culture, in small organisms that are relatively transparent (Drosophila) or two-dimensional (plant leaves), and in ex vivo analyses after expression in larger animals. In such assays reporter genes are linked to genetic regulatory elements and can reveal spatial and temporal information about a variety of biological processes at the level of transcription. The goal of real-time analysis of biological events in intact living mammals was recently realized in our laboratories". Two key observations lead to the development of this technology. The first observation was that biological sources of light are sufficiently intense such that the light generated within a mammal can be detected externally". The second observation was that substrate, either endogenous (bacterial) or exogenous (insect), could be made available to biolumi-nescent reporters in living mammals"". We have employed sensitive detection devices to visualize and quantify bioluminescent light by detecting photons that are transmitted through mammalian tissue from internal sources". Several technical advances for imaging weak visible light sources using charged coupled device (CCD) cameras have emerged recently and include microchannel plate intensifiers, Peltier or liquid nitrogen cooling of the detector, and a combination where the intensifier, and not the CCD detector, is cooled. The goal of these technologies is to enhance signal-tonoise ratios by either reducing background (cooled) or increasing signal (intensified). These instruments have broad application in science and industry and are available from a variety of commercial sources. A Hamamatsu intensified CCD (ICCD, model C2400-32) has been used for monitoring infection and gene expression in living mammals in our laboratories.