英语科普小知识 疱疹病毒如何入侵神经系统

海量资料下载 免费学习英语 www.englishvip.com/xinlw.htm （申请网址） Northwestern Medicine scientists have identified a component of the herpesvirus（疱疹病毒）that "hijacks" machinery inside human cells, allowing the virus to rapidly and successfully invade the nervous system upon initial exposure. Led by Gregory Smith, associate professor in immunology and microbiology at Northwestern University Feinberg School of Medicine, researchers found that viral protein 1-2, or VP1/2, allows the herpesvirus to interact with cellular motors, known as dynein（动力蛋白）. Once the protein has overtaken this motor, the virus can speed along intercellular highways, or microtubules, to move unobstructed from the tips of nerves in skin to the nuclei of neurons within the nervous system.   This is the first time researchers have shown a viral protein directly engaging andsubverting（颠覆，推翻） the cellular motor; most other viruses passively hitch a ride into the nervous system.   "This protein not only grabs the wheel, it steps on the gas," says Smith. "Overtaking the cellular motor to invade the nervous system is a complicated accomplishment that most viruses are incapable of achieving. Yet the herpesvirus uses one protein, no others required, to transport its genetic information over long distances without stopping."   Herpesvirus is widespread in humans and affects more than 90 percent of adults in the United States. It is associated with several types of recurring diseases, including cold sores, genital herpes, chicken pox, and shingles. The virus can live dormant in humans for a lifetime, and most infected people do not know they are disease carriers. The virus can occasionally turn deadly, resulting in encephalitis in some.   Until now, scientists knew that herpesviruses travel quickly to reach neurons located deep inside the body, but the mechanism by which they advance remained a mystery.   Smith's team conducted a variety of experiments with VP1/2 to demonstrate its important role in transporting the virus, including artificial activation and genetic mutation of the protein. The team studied the herpesvirus in animals, and also in human and animal cells in culture under high-resolution microscopy. In one experiment, scientists mutated the virus with a slower form of the protein dyed red, and raced it against a healthy virus dyed green. They observed that the healthy virus outran the mutated version down nerves to the neuron body to insert DNA and establish infection.   "Remarkably, this viral protein can be artificially activated, and in these conditions it zips around within cells in the absence of any virus. It is striking to watch," Smith says. 西北医学科学家们已经确定的一个组成部分的疱疹病毒（疱疹病毒），“劫持”机械内部人体细胞，使病毒迅速和成功地侵入神经 ​​系统在初始曝光。格雷戈里·史密斯的带领下，在西北大学范伯格医学院的免疫学和微生物学副教授，研究人员发现，病毒蛋白1-2或VP1 / 2，允许与蜂窝电机，动力蛋白被称为疱疹病毒（动力蛋白）。一旦蛋白已经超越了这种电机中，该病毒可以加快沿间公路，或微管，从皮肤神经的提示神经系统内的神经元的细胞核移动通畅。   这是研究人员首次明一种病毒蛋白直接从事颠覆（颠覆，推翻）蜂窝电动机;被动大多数其他病毒进入神经 ​​系统搭顺风车。   “这种蛋白质不仅抓住方向盘，步骤上气，”史密斯说。“超英赶美的蜂窝电动机侵入神经系统是一个复杂的成就，大多数病毒是无法实现的，但是疱疹病毒使用了一种蛋白质，没有其他需要，长距离运输的遗传信息，而无需停止。”   疱疹病毒广泛存在于人类和影响在美国90％以上的成年人。它是伴随着经常性的疾病，包括感冒疮，生殖器疱疹，水痘和带状疱疹的几种类型的。该病毒可住蛰伏在人类的一生，和大多数受感染的人不知道他们是疾病的载体。该病毒可偶尔会导致致命的后果，导致在某些脑炎。   直到现在，科学家们知道，的疱疹病毒旅游迅速到达位于身体内部的深层神经元，但这一机制的推进仍然是一个谜。   史密斯的研究小组进行了各种实验与VP1 / 2展示其重要的作用，在输送病毒，包括人工激活和基因突变的蛋白质。该小组研究了在动物体内的疱疹病毒，并且也高分辨率显微镜下，在人类和动物细胞的培养。在一项实验中，科学家突变病毒的蛋白质染成红色较慢的形式，比赛，对一个健康的病毒染成绿色。他们观察到，健康的病毒抽掉下来神经的神经元体的突变版本中插入的DNA，并建立感染。   “值得注意的是，这种病毒蛋白质可以人为地被激活，并在这些条件下，周围的拉链在没有任何病毒在细胞内的，令人吃惊的观看，”Smith说。 “成千上万人疯狂下载。。。。。。 更多价值连城的绝密英语学习资料， 洛基内部秘密英语，技巧，策略 请在 网上 申请报名” 洛基国际英语 竭诚为您服务