Scientists can finally explain exactly how and why a cell's defences fail against some invaders, including the plague, while successfully fending off others.
A new super-resolution microscopy technique is providing researchers with never-before-seen detail of a cell membrane.
Jesse Aaron, a researcher at of Sandia National Laboratories, said: "We're trying to do molecular biology with a microscope, but in order to do that, we must be able to look at things on a molecular scale."
The development could open doors to new diagnostic, prevention and treatment techniques.
Receptor proteins on the surface of immune cells, known as toll-like receptors (TLRs), are tasked with recognising intruders.
The TLR4 member of this receptor family responds to certain types of bacteria by detecting lipopolysaccharides (LPS) present on their surface. Then the TLR4 proteins alert the cell and activate an immune response.

Using the techniques they developed, researchers discovered that TLR4 proteins cluster in the membrane when confronted with LPS derived from E.coli, which increases cell signalling and response.
While LPS derived from the bacteria that cause plague do not cause the same effects.
This could explain why some pathogens are able to thwart the human immune system.
The plague studies marked the first time such small events have been imaged and compared, the researchers said.


科学家们终于可以准确解释细胞的防御系统是如何成功避开某些病菌入侵，而它又为何不能抵御另一些病菌侵袭的，例如瘟疫。

一项新的超分辨率显微镜技术为研究人员展示了他们前所未见的细胞膜的细节。

圣地亚国家实验室的一名研究员杰西•亚伦说："我们想利用显微镜做一个关于分子生物的研究，但是，前提是我们观测事物必须要在分子水平上。"

这个进步为未来研究新的诊断、预防及治疗技术打开了一扇门。

免疫细胞表面的受体蛋白质，就是通常所说的Toll样受体，它的任务是识别入侵抗原。

TLR4是Toll样受体的一种，它通过检测附着在细菌表面的脂多糖来对特定类型的细菌做出反应并警示细胞同时激活免疫响应。

通过使用这种成像技术，研究人员发现TLR4蛋白质遇到来自大肠杆菌的脂多糖时会聚集在细胞膜内，提高细胞发出信号和反应的能力。

而当TLR4蛋白遇到可以产生瘟疫的细菌表面的脂多糖时就不会发生上述反应。

这就可以解释为什么一些病原体能够侵袭人类的免疫系统。
据研究人员介绍，就如此细小的现象做成像和比较的病原体研究也还是头一回。

• treatment [´tri:tmənt] n.待遇；对待；治疗 (初中英语单词)
• cluster [´klʌstə] n.一串 v.群集；丛生 (初中英语单词)
• plague [pleig] n.瘟疫 vt.使...染疫 (高中英语单词)
• successfully [sək´sesfəli] ad.成功地 (高中英语单词)
• response [ri´spɔns] n.回答；响应 (高中英语单词)
• trying [´traiiŋ] a.难堪的；费劲的 (英语四级单词)
• biology [bai´ɔlədʒi] n.生物学，生态学 (英语四级单词)
• microscope [´maikrəskəup] n.显微镜 (英语四级单词)
• prevention [pri´venʃən] n.预防；阻止；妨碍 (英语四级单词)
• bacteria [bæk´tiəriə] n.细菌 (英语四级单词)
• membrane [´membrein] n.膜(片)；薄膜；隔膜 (英语四级单词)
• thwart [θwɔ:t] vt.阻挠 a.横(断的) (英语四级单词)
• technique [tek´ni:k] n.技术；技巧；方法 (英语六级单词)