2022年经济学人 狡猾的细菌(1)

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Science & technology

科技板块

Immunology

免疫学

Fed by the hand that should bite it

已攻击自己的东西为食

A bacterium¹ that tricks the immune system into nurturing² it

一种欺骗免疫系统培养它的细菌

The immune system has many weapons with which to counter hostile incomers.

免疫系统有许多武器可以用来对抗敌对的入侵者。

But what works against one may not be effective against another.

但对一种病毒起作用的方法对另一种可能不起作用。

An interloper can take advantage of this by misdirecting the system into thinking it is fighting an enemy that it is not.

入侵者可以利用这一点，误导系统，让它们认为自己正在与另一个敌人作战，而实际上并非如此。

This buys time for that interloper to become entrenched³.

这为闯入者扎根赢得了时间。

That is sneaky.

这太狡猾了。

Sneakier still, though, is the approach just discovered by Ruslan Medzhitov of Yale University.

不过，耶鲁大学的鲁斯兰·梅德日托夫刚刚发现的方法更“狡猾”。

As he and his colleagues report in Immunity⁴, they have found a bacterium that induces its host’s immune system to release compounds on which it can then feed.

正如他和他的同事在《免疫》杂志上报道的那样，他们发现了一种细菌，它可以诱导宿主的免疫系统释放出化合物，并以此为食。

Mammalian immune systems have two modes of attack.

哺乳动物的免疫系统有两种攻击模式。

Type-1 is used against bacteria and viruses; type-2 against multicellular parasites⁵ such as worms.

类型1用于对抗细菌和病毒；类型2用于对抗多细胞寄生虫，如蠕虫。

Some invading bacteria, however, provoke a type-2 response when type-1 would be appropriate.

然而，一些入侵的细菌会在适合类型1的攻击模式下引发类型2的反应。

Dr Medzhitov decided⁶ to take a closer look.

梅德日托夫博士决定更进一步观察。

He and his colleagues studied the behaviour of Pseudomonas aeruginosa, a bacterium which causes stubborn infections in people with cystic fibrosis.

他和他的同事研究了铜绿假单胞菌的行为，这是一种导致囊性纤维症患者顽固感染的细菌。

They suspected it was leading the body to mount an ineffective type-2 response against it and wanted to know how it was doing this.

他们怀疑这是导致身体对它进行无效的2型反应，并想知道它是如何做到这一点的。

To explore the matter, they grew laboratory cultures of the sorts of epithelial cells that line human airways⁷ and monitored their gene-expression profiles when exposed to LasB, a toxic⁸ enzyme⁹ produced by the bacterium.

为了探究这一问题，他们在实验室培养了人体呼吸道内的各种上皮细胞，并监测了它们在接触LasB时的基因表达谱，LasB是一种由细菌产生的有毒酶。

They found that LasB activated¹⁰ signalling pathways which drove the epithelial cells to make a protein called amphiregulin.

他们发现LasB激活了信号通路，驱动上皮细胞产生一种名为双调节蛋白的蛋白质。

This forms the basis of a thick mucus that excels at ensnaring parasitic¹¹ worms.

这形成了厚厚的粘液的基础，这种粘液擅长诱捕寄生虫。

It also recruits immune cells called eosinophils, which are adept¹² at attacking multicellular parasites.

它还影响了被称为嗜酸性粒细胞的免疫细胞，这种细胞擅长攻击多细胞寄生虫。

1 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

2 nurturing   

养育( nurture的现在分词 )； 培育； 滋长； 助长

参考例句：

• These delicate plants need careful nurturing. 这些幼嫩的植物需要精心培育。
• The modern conservatory is not an environment for nurturing plants. 这个现代化温室的环境不适合培育植物。

3 entrenched   

adj.确立的，不容易改的(风俗习惯)

参考例句：

• Television seems to be firmly entrenched as the number one medium for national advertising.电视看来要在全国广告媒介中牢固地占据头等位置。
• If the enemy dares to attack us in these entrenched positions,we will make short work of them.如果敌人胆敢进攻我们固守的阵地，我们就消灭他们。

4 immunity   

n.优惠；免除；豁免，豁免权

参考例句：

• The law gives public schools immunity from taxation.法律免除公立学校的纳税义务。
• He claims diplomatic immunity to avoid being arrested.他要求外交豁免以便避免被捕。

5 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

6 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

7 AIRWAYS   

航空公司

参考例句：

• The giant jets that increasingly dominate the world's airways. 越来越称雄于世界航线的巨型喷气机。
• At one point the company bought from Nippon Airways a 727 jet. 有一次公司从日本航空公司买了一架727型喷气机。

8 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

9 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

10 activated   

adj. 激活的 动词activate的过去式和过去分词

参考例句：

• The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。

11 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

12 adept   

adj.老练的，精通的

参考例句：

• When it comes to photography,I'm not an adept.要说照相，我不是内行。
• He was highly adept at avoiding trouble.他十分善于避开麻烦。