【经济学人】实验小鼠是否太过干净？丨2017.3.23丨总第849期

If modern human homes are unnaturally clean, though, they are as nothing compared with the facilities in which experimental mice are housed. Those are practically sterile. That led Lili Tao and Tiffany Reese, two researchers at the University of Texas Southwestern Medical Centre, in Dallas , to wonder if such mice would display extreme versions of the predictions of the hygiene hypothesis.

虽然现代人类的住所及其干净，却也无法与侍养实验小鼠的环境相比，它们居住的环境近乎无菌。这引发了达拉斯德州西南医学中心的两位研究人员Lili Tao和Tiffany Reese去研究这些老鼠在卫生假说预测上是否会表现出极端的状况。

• Dallas：n.达拉斯（地名）

This would matter, because mice are often used in medical experiments on the assumption that their reactions are similar enough to those of human beings for them to act as stand-ins . Conversely, laboratories’ spotlessness might also mean mice are sometimes too healthy to act as useful models for disease. As they explain in Trends in Immunology, Dr Tao and Dr Reese therefore combed the scientific literature to look for both phenomena.

这很重要，因为一般都假设老鼠的对药物的反应与人类的反应基本相同，故经常作为人类的替身，被用于医学实验。但是，干净清洁的实验室意味着小鼠过于健康，因此小鼠有时甚至都不适合作为研究疾病的有效模型。正如他们在《免疫学趋势》杂志中所说的，为了找到这两种现象，Tao博士和Reese博士搜查了所有的科学文献。

• stand-ins：n.替代品

A nice example which the two researchers found of the hygiene hypothesis at work is that stopping laboratory mice being infected with murine cytomegalovirus , which is common in their wild kin, damages their immune response to a host of other pathogens, bacterial as well as viral. Mice so infected will survive subsequent exposure to otherwise-lethal doses of Listeria monocytogenes (a soil- and food-borne bacterium) and Yersinia pestis (the bacterium that causes plague ). These mice are also better able than others to handle retrovirus infections. And the effects on them of multiple sclerosis —an illness the underlying cause of which is suspected to be an inappropriate immune response—are reduced.

两位研究人员在研究中发现的一个关于卫生假说的恰当例子就是，避免实验小鼠感染在野生亲缘常见的鼠巨细胞病毒，这种病毒（包括细菌和病毒）会损害它们对许多其他病原体的免疫反应。被感染的小鼠放在致死剂量的单核细胞增多性李斯特氏菌(土壤和食源性细菌)和鼠疫耶尔森菌(引起鼠疫的细菌)中也能存活。这些小鼠也比其他小鼠更能够抵抗逆转录病毒感染，而且减小了多发性硬化（该病的根本原因被认为是不恰当免疫反应）对它们的影响。