人体奥妙之细胞的暗战（2012）

flags warning of the invasion that has taken place.
假如这个信♥号♥♥被巡逻的白细胞发现
If patrolling white blood cells spot the distress signal...
它们会将被感染的细胞
they will destroy the cell,
连同其内部的病毒大军一起消灭
along with the entire alien army inside.
但如果没被发现 病毒将会扩散
If not, the infection will spread
感染所有细胞
from cell to cell, to cell.
病毒占领细胞仅一天之后
After just one day of occupation,
就已取得了全面控制权
the virus has complete control over the cell.
随着正常给养的停止 细胞开始衰败
With routine maintenance halted, the cell has started to decay.
仅有的活动
And all activity is now
就是在细胞核内
focused on building the brand new viral army
制♥造♥新的病毒大军
inside the nucleus.
新军队可以自动组装
The new army self-assembles.
病毒怎么知道如何入侵人体细胞
How do viruses know how to invade our cells,
如何冲破防御并进入细胞核呢
how to break and enter the nucleus itself?
我们知道病毒与细胞协
同进化了
We know that viruses and cells co-evolved
很长时间 但还不止于此
together over long periods of time, but it's more than that.
它们之间还有着惊人的密切关系
We're actually surprisingly closely related.
原来 攻击我们的病毒
It turns out that the viruses that attack us
正是由人体自身的细胞碎片演变而成
are actually made from bits and pieces of our own cells.
随着细胞的进化
As our cells were evolving,
在细胞核成形的初期
as our nucleus itself was first coming to be,
病毒也由碎片拼凑而成
so these viruses were cobbled together from bits and pieces.
它们之所以能攻击细胞核
And they can attack our nucleus
是因为它们也是由相同的物质组成
because they're made of the same stuff.
最先在病毒表面组装的是
Already built into its surface are the binding sites
细胞机动腿的结合位点
for the cell's motorised legs.
随后 纤维接入对应的位置
Fibres snap into place,
为病毒配备入侵细胞的钥匙
arming each virus with the keys to enter other cells.
但除非得到指令 这层衣壳是无害的
But these shells are harmless without its instructions.
因此 最后的组件
The final component is loaded -
也就是致命的病毒DNA
identical copies of the virus's deadly DNA.
经由强大的马达蛋白
Carried by powerful motors,
注入每一个病毒内
long strands of DNA are fed into every single virus.
这一切的起源 只不过是
All this is the result of one single virus
细胞防御被一个病毒突破了
getting through our cell's defences.
此时 病毒进入人体已经两天了
It's been two days since the virus entered the body,
而曾是细胞控制中心的细胞核
and the nucleus, once the centre of cellular organisation,
成为了上万病毒大军的避风港
now harbours an army of 10,000 deadly viruses.
但在病毒开始攻城略地之前
But before it can begin its conquest,
还需要再攻克两重障碍
it has to overcome two barriers.
大军仍然被包裹在细胞中♥央♥
The army is trapped inside the tough nuclear membrane,
坚韧的核膜内
held at the centre of the cell itself.
此外 细胞膜也依然存在
And then there is the skin of the cell itself.
细胞核外的蛋白质工厂 在病毒指示下
The protein factories outside the nucleus are instructed
开始制♥造♥破坏性蛋白
to build viral saboteurs.
第一种破坏蛋白被释放到衰败的细胞中
The first are released into the decaying cell
专门攻击细胞骨架
and target its cytoskeleton.
这次攻击是灾难性的
The effects are cataclysmic.
失去骨架的支撑
Without support
细胞开始塌陷
the cell starts to collapse.
此时 病毒又将注意力转向核膜
Now the virus turns its attention to the nuclear membrane.
并释放出第二种破坏蛋白质
A second protein is released.
名叫腺病毒死亡蛋白
Called the Adenovirus Death Protein,
它钻入核膜
it burrows into the membrane
并将其削弱
and weakens it.
细胞核再也无法容纳激增的病毒
The nucleus can no longer contain the bulging army.
细胞核之外 已是一片废墟
Beyond the nucleus, the cell is a wasteland...
仅仅48小时前的那个和谐欢乐的社区
Unrecognisable from the harmonious, buzzing community
现已面目全非
of just 48 hours ago.
至此 细胞已无回天之力
The cell is now completely helpless to stop the virus army
病毒像洪水般地涌向周围的组织
from flooding into surrounding tissue
攻击临近的细胞
attacking neighbouring cells
并将感染扩散到全身
and spreading infection throughout the body.
对这个细胞来说 战役已结束
The battle for this cell is over.
但真正的战争才刚刚打响
But the war has only just begun.
当病毒还在细胞内部忙碌时
While the virus has been busy inside the cell,
我们的抗体已完成改造 并重返战场
our antibodies have adapted and now come back in force,
它们装上了新的受体
carrying new receptors,
为敌人量身定制的封锁武器
tailor-made to lock onto the escaping army.
然而 即使抗体数量庞大
Yet even in these numbers,
仍然无法阻止所有病毒
they cannot stop every virus.
但它们有战友
But they are not alone.
细胞垂死之际发出的信♥号♥♥没有白费
The cell's dying message to the outside world was not in vain.
巨型白细胞向被侵略的细胞聚集
Giant white blood cells flock to the stricken cell
吞噬逃逸的病毒
to devour the escaping hordes.
它们也在学习如何击败这些入侵者
They too are learning how to tackle this particular invader.
一旦病毒被免疫系统发现
Once the virus has been detected by the immune system,
你体内的安全系统便会提升级别
there's a heightened level of security inside your body,
其益处就是
and one of the results of this
负责生产抗体的细胞
is that the cells that make antibodies,
将生产出专门针对这种病毒的抗体
and make the right antibody for that virus,
并复♥制♥出大量和自身一样的白细胞
will make lots of copies of themselves,
它们以每秒生产五千个的速度
and then they will start pumping out
释放大量抗体
up to 5,000 antibodies per second
涌入血液和细胞间隙 拓展防线
to flood your bloodstream, the spaces between your cells,
当病毒从临死的细胞中涌出时
so as the viruses emerge from dying cells,
它们会被抗体标记
they can get tagged by antibodies,
然后被白细胞消灭
then destroyed by white blood cells.
为保万无一失
Taking no chances,
白细胞会吞噬附近所有可能被感染的细胞
white blood cells engulf nearby cells that may have been infected.
与此同时
Meanwhile,
周围的健康细胞也做出最伟大的牺牲
surrounding healthy cells make the ultimate sacrifice,
毁灭自己 以阻止病毒的传播
destroying themselves to stop the spread of the virus.
只有到了这个阶段
It is only at this stage
我们才会意识到发生在自己体内的战役
that we become aware of the battle taking place inside us.
加速的血流
Increasing blood flow
将更多白细胞送抵战场
brings more white blood cells to the battleground,
导致鼻部组织充血红肿
causing our nasal tissue to become inflamed.
我们感觉到的鼻塞 实际上
What we feel is a blocked nose is, in fact,
正是猛烈攻击病毒的迹象
the clearest sign of a viral onslaught.
一旦被一种病毒感染过
Once you've had an infection,
能制♥造♥对付该病毒抗体的白细胞
one cell, that makes the antibody for that infection,
将永远保留在你的骨髓中
will be kept inside your bone marrow for the rest of your life.
如果你再次感染同种病毒
So that if you ever get another infection with the same virus,
免疫系统会知道如何应对
the immune system already knows how to respond,
知道应制♥造♥哪种抗体
it knows what antibody to make
并可迅速做出反应 免去你病痛之苦
and it can respond very quickly and stop you getting sick.
依靠团队合作 人体的免疫系统
Working together, the body's immune system finally prevents
终于阻止了病毒感染的扩散
the viral infection from spreading.
这只是永无休止战争中的一场战役
It's one more battle in an unending war.
人类和病毒之间的战争便是进化
The struggle between viruses and ourselves is evolution,
但这是协同进化 双方都必须改变
but it's co-evolution - both sides have to change.
就像是一场军备竞赛
It's a bit like an arms race,
一方得到了更好的武器
one party gets better weapons,
另一方也得跟上
the other party has to match them.
即使单个细胞在与病毒进行
Even though the individual cells are fighting this epic battle
史诗般的对决
against viruses,
要记得 你有数以万亿记的细胞
remember, you have trillions of cells.
虽然独个细胞战败了
And so even if one cell loses its war,
但大多数时候 人体仍能取胜并康复
most of the time the organism wins and we get better.
战斗结束了
The war is over.
暂时如此
For now.
虽然失去了很多细胞
Although many cells have been lost,
但有更多健康的细胞将取代它们
there are many more healthy cells waiting to replace them.
每个细胞的核心
And at the heart of each one
含有一个与我们DNA相同的副本
lies an identical copy of our DNA.
经由我们的父母
Inherited from our parents,
以及他们无数代的祖先遗传下来
and their parents over countless generations,
人类的DNA可以追溯至
our DNA connects us to a family tree that stretches back