人体奥妙之细胞的暗战（2012）

since the adenovirus first attacked the cell.
入侵细胞核只需再花一个小时
The nucleus is just one more hour away.
科学家们一直以为一旦病毒大军涌入
Until recently, scientists thought that once the viral army
就没有什么能够阻止它们
was on the march, nothing could stop it.
但直到近期他们发现
But then they found that
细胞自身也有一套内部免疫系统
the cell has its own internal immune system.
细胞内部有一整套
There is this whole mechanism inside cells
消灭病毒的机制
that are taking out viruses
我们之前一直都没有发现
that previously we just didn’t know was there.
我记得我们发表论文的那天
And I remember the day we published the paper about it,
我醒来听到国家广播电台正在公布这条讯息
I woke up to hear it being announced on the national radio
然后我去商店买♥♥了一份报纸
and then went into a shop to pick up the newspapers
发现它被刊登在了头版
to discover it was on the front page.
有一种特殊的蛋白质
Dotted along the cell’s highway system,
分布在细胞运输系统各处搜寻
a special protein searches for anything carrying antibodies
携带抗体的物质
from the surface.
这种蛋白的绝妙之处在于
The clever thing about this protein is it uses systems
它运用了细胞原有的系统
that the cell already has in place.
一旦附着于抗体
Once it’s stuck to the antibody,
它就会向名叫蛋白酶体的细胞机
it sends signals to a cellular machine
发出信♥号♥♥
called the proteasome.
蛋白酶体在细胞中起到回收蛋白的作用
And the proteasome plays the role of recycling proteins in the cell.
它被招来将病毒摧毁
It gets brought along to the virus and it destroys the virus,
分解成非常小的碎块
breaking down all its parts into tiny fragments.
一旦依附
Once attached,
防御蛋白就会启动连锁反应
the defence protein initiates a chain reaction,
吸引特殊的标记蛋白
attracting specialised tagging proteins.
它们一起将病毒标上摧毁记号♥
Together, they mark the virus for destruction.
接下来只是时间问题了
Then it’s only a matter of time…
等待回收机的到来
before the recyclers arrive.
它们把病毒绞成碎片
They rip the virus to shreds.
在你体内的某处
Somewhere inside your body,
这场战争正在激烈地进行着
this battle is raging right now.
TRIM21蛋白的发现 或许能提供
The discovery of TRIM21 provides potentially new ways
对抗病毒的新途径
of making therapeutics to fight viruses,
其中一个途径
and one way this could work is
就是想办法促进免疫系统
if we find ways of encouraging the immune system
制♥造♥更多TRIM21
to make more TRIM21.
那么 当病毒进入细胞内时
So as soon as that virus enters into the cell,
TRIM21就会立即
the TRIM21 is ready
识别出抗体并将病毒消灭
to recognise the antibodies and destroy the virus.
在防御蛋白和回收机的共同努力下
By working together, the defence proteins and recycling shredders
几小时内就能歼灭病毒大军
can destroy an army of viruses in just a few hours.
然而 往往只需一个病毒
But it only takes a single virus
便能控制整个细胞
to take control of an entire cell…
感染就会传播到全身
spreading infection throughout the body.
没有抗体粘附
With no antibodies attached,
这个病毒逃脱了被粉碎的命运
this virus has evaded the cell’s shredders.
通向细胞核的道路畅通无阻
Nothing now stands between it and its target.
病毒距细胞核仅有
The virus is now just one thousandth of a millimetre
千分之一毫米
from the nucleus.
但想完成终极目标
But if it is to achieve its ultimate goal,
首先要想办法进去
it first has to get inside.
和细胞相比 病毒极其微小
Compared to the cell, the virus is tiny.
但实际上它们只是同类机器的不同版本
But really they’re just different versions of the same machine,
目的都是为了复♥制♥自己
and its only job is to copy itself.
但病毒却需要利用人体细胞的机制
But the virus needs to take advantage of our cell mechanism
来达到它自私的目的
for its own selfish ends.
细胞核居于每个细胞的中心
At the heart of every cell lies the nucleus,
它拥有一个属于自己的世界
and it is a world all of its own.
组成它的表面的分子与细胞膜同种
Its surface is made of the same molecules as the cell membrane.
但这个世界的入口
But entry into this world
却由完全不同的通道掌控
is governed by completely different gateways.
在其表面
Across the surface,
蛋白触角搜寻着分子并将其拉入核孔中
protein arms search for molecules to draw inside nuclear pores.
数十亿条化学信♥号♥♥和指令透过这些通道
Through these gateways, billions of chemical messages
在DNA和细胞之间相互传递
and instructions pass between the DNA and the cell.
但这些信♥号♥♥必须能被蛋白触角识别
But only if they are recognised by the protein arms.
而病毒衣壳上仍有伪造的通行证
But once again, the viral shell carries a counterfeit pass.
触角将其锁定
The arms lock on,
但病毒过大 无法进入
but the virus is too large to be ferried inside.
马达蛋白以为遇到了障碍物
Thinking that they have hit an obstruction,
于是将病毒向反方向移♥动♥
the motor proteins shunt the virus into reverse.
受到两个方向的拉力
Pulled in two directions…
病毒被撕裂了
the virus is ripped apart.
这看似病毒的劫难 事实上
But what looks like a catastrophe for the virus,
却正是它的绝招
is in fact, its masterstroke.
现在 病毒内部的DNA
Now the single strand of DNA it held inside
穿过核孔
is carried through the pore,
被带入了细胞的控制中心
and into the cell’s control centre.
人类细胞核中含有大约两万三千个基因
Inside the human cell nucleus there are about 23,000 genes.
编码了数千个生化途径
They code for thousands and thousands of biochemical pathways.
然而病毒只有40个
The virus has just got 40,
但仅凭40个 它也可以有一番作为
but with those 40 it can do remarkable things.
它如此之小 只含有一小段DNA
It’s so tiny, just a piece of DNA,
用一些蛋白质作外壳
a couple of proteins to make its shell,
而它却能占领
and yet it can take over
一个巨大的人体细胞并造成严重破坏
and wreak havoc in a huge human cell.
真的太神奇了
It’s brilliant.
腺病毒已经证明了自己是个欺诈高手
The adenovirus has proven itself a master of deception…
不断利用细胞的机制
Continually exploiting the cell’s processes
来达到自己的终极目标
to further its own deadly aims.
但它最妙的诡计还未上演
But its greatest trick is yet to come.
细胞的DNA机械无法区分
The cell’s DNA machines have no way of telling the difference
自身DNA与病毒DNA
between its own DNA and the DNA of the virus.
它们开始盲目地将病毒的遗传编码
Blindly, they set about converting its deadly code
转录为给细胞的执行指令
into thousands of instructions for the cell to act upon…
绘出了自我毁灭的蓝图
blueprints for the cell’s own destruction.
但是把指令转换为蛋白质的机器
But the machines that turn the blueprints into proteins
位于细胞核外
lie outside the nucleus.
在细胞主体中 指令会被传达给
Out in the main body of the cell, the instructions are met
一群流动的蛋白质工厂 即核糖体
by a squadron of mobile protein factories, called ribosomes.
核糖体精确地遵照指示
The ribosomes precisely follow the instruction
开始建造病毒蛋白
and start to construct viral proteins.
每个核糖体都具有独特的形状
Each is carefully folded into a specific shape,
并被赋予特殊的职责
with a unique job to do.
核糖体 这种大型细胞机
These large cellular machines, ribosomes,
对生命来说 至关重要
are absolutely fundamental to life,
地球上每一种细胞中都含有
and very similar forms of them are found in every type
形态相近的核糖体
of living cell on the planet.
它们可以读取并破译遗传信息
They read the genetic information and they decode it,
将构成蛋白质的基本单位
bringing in the building blocks that make up proteins
粘在一起 制♥造♥出能在细胞中
and sticking them together to make these functional molecules
正常工作的功能分子
that are going to work inside the living cell.
可是这些功能分子
Only these functional molecules
正是建造病毒大军所需的材料
are the kit of parts needed to build an enemy army.
军队无法再细胞核外建造
But the army will not be built out here.
所有建造军队的材料
The raw material for the new army
又被送回到细胞核内部
is drawn back inside the nucleus…
准备开工
Ready for construction.
当使命即将完成时
With its mission reaching its climax,
病毒把注意力转向了细胞的DNA
the virus turns its attention to the cell’s DNA,
停止任何不需要的程序
halting any process it doesn’t need.
病毒已将细胞完全控制
The virus has taken complete control.
但细胞反♥攻♥还有最后一线希望
And yet the cell still has a small window of opportunity.
在细胞正常运作被停止前
Before all normal activity stops,
它利用最后的时间向外界发送了一个信息
it has just enough time to send a message to the outside world.
这个囊泡中包含了病毒的碎片
This parcel contains fragments of the viral army.
囊泡与细胞膜融合
The parcel merges with the cell membrane,
将病毒碎片运送出细胞
and the enemy fragments are pushed to the surface,
发出已被攻克的警告