未登录,请登录后再发表信息
最新评论 (0)
播放视频

为什么疱疹是有史以来最天才的病毒

Why Herpes Is the Most Talented Virus Ever

Getting sick is never pleasant,
生病从来都不是好事
but at least many viral infections are one-and-done.
但好歹很多病毒一个人一生只会感染一次
We’ve talked before about how the measles virus
之前我们提到的麻疹病毒
is the poster child for lifelong immunity.
就是终身免疫型病毒的一种典型
Once your immune system recognizes it,
免疫系统只要见过这种病毒
it never forgets,
就永远记得它
and it will not hesitate to kick it to the curb if it shows its face again.
它一露面 免疫系统就会立马将它挡在门外
Unfortunately, however, there’s also a poster child for lifelong infection:
可惜 终身感染型病毒也有一种典型
herpesviruses.
即疱疹病毒
These viruses are so good at sneaking past our immune system
它特别擅长从免疫系统眼皮子底下溜走
and hiding out in our cells
并且躲进我们的细胞
that once we have ‘em, we… have ‘em.
所以一旦感染 病毒就会一直存在
Because herpesviruses have some unique features
因为疱疹病毒有一些独特之处
that make them master squatters,
能让它们成为侵入人体的高手
which seems kind of embarrassing for our immune systems,
免疫系统似乎都得为之汗颜
but actually, we may have evolved to coexist.
但事实上 我们可能已经学会了与疱疹病毒共存
There are eight members of the herpesvirus family that routinely infect humans.
有八种疱疹病毒通常会感染人类
These include herpes simplex virus 1 and 2,
包括能引发口腔与生殖器疱疹的
which cause oral and genital herpes,
单纯疱疹病毒1型和2型
as well as the viruses that cause chickenpox and shingles,
能引起水痘 带状疱疹的病毒
and most — but not all —cases of mononucleosis, or mono.
以及引发大多数 但不是所有单核细胞增多症的病毒
Herpesviruses are nearly everywhere.
疱疹病毒几乎无处不在
It’s thought that more people on this planet
或许全世界感染单纯疱疹病毒1型的人
are infected with herpes simplex 1 than not.
比没感染的还要多
Herpesviruses are known for being unusually large and complex, as viruses go.
在病毒中 疱疹病毒以体积极大 组成复杂著称
Their genomes are so large, with so many different genes,
疱疹病毒的基因组庞大而多样
that they can make dozens or even hundreds of proteins.
能够制造多达上百种蛋白质
That’s way more than other viruses,
比其他病毒能制造的多得多
influenza virus genomes for instance, only make twelve proteins.
比如 流感病毒就只能制造十二种蛋白质
These proteins give herpes all kinds of tools
正因为这些蛋白质 疱疹病毒才有了各种手段
that let it infect a host…forever.
让自己永远都能感染宿主
Like a gang of thieves in a heist flick,
就像一伙抢劫电影里的窃贼
these viruses slip past all of the traps and defenses
疱疹病毒能够依次避开
our body puts out for them, one by one.
人体布下的所有陷阱和防御措施
First, herpesviruses have to get past our innate immune system —
首先 疱疹病毒需要通过人体的先天免疫系统
the part of our immune system that holds off new, unknown invaders,
这种免疫系统会抵御全新且未知的侵入物
without being noticed.
疱疹病毒需要偷偷侵入
It’s a sneaky move known as immune evasion.
这招叫免疫逃避
The innate immune system’s first line of defense against new threats
先天免疫系统抵御威胁的第一道防线
starts with the production of proteins
从生产蛋白质开始
that kick cells into bouncer mode,
让细胞启动防卫模式
setting off a huge signal cascade
释放一大串信号
that ultimately prevents viruses from using host cells to replicate.
最终阻止病毒利用宿主细胞复制繁衍
But herpesviruses reduce the cell’s production of those bouncer proteins,
但疱疹病毒会减少细胞生成蛋白质的数量
which dampens cells’ first line of defense.
细胞保卫性降低 第一道防线效果就打了折扣
But cells have backup defenses against viruses that can get past this pathway,
但细胞有备用手段抵御通过这道防线的病毒
which herpes also has an answer to.
然而疱疹病毒也有对策
Herpesviruses can integrate themselves into the host’s DNA,
疱疹病毒能与宿主的DNA融合
which can cause damage to host’s genome.
损害宿主的基因组
And cells are normally super vigilant about monitoring for DNA damage.
一般来说 细胞对DNA损伤的监视保持高度警惕
But herpes can convince them to overlook it.
但疱疹病毒能让细胞对DNA损伤不管不顾
For example, herpes simplex virus 1 produces proteins
例如 单纯疱疹细胞1型就能制造蛋白质
that basically sabotage the cell’s DNA damage warning
破坏细胞的DNA损伤预警与修复机制
and repair machinery and take it over.
从而占领细胞
The next trap seems inescapable:
下一个陷阱似乎让病毒无处可逃
When all else fails, a cell making a last-ditch effort
细胞会自我牺牲
to contain a virus will basically kill itself.
尽最大的努力来吞噬病毒
But you probably know where we’re going with this by now.
但你现在可能也知道病毒如何逃过此劫
Herpes has proteins that can evade the cell’s self-destruct signals.
疱疹病毒有能避开细胞自毁信号的蛋白质
Once it gets past the innate immune system,
通过先天免疫系统之后
herpes has to stay out of trouble long enough
疱疹病毒需要长时间保持低调
to set up camp within the host’s cells.
以便在宿主细胞内安营扎寨
While it’s working on that, herpes is in what virologists call the lytic phase —
病毒学家将这一时期称为裂解期
it’s actively reproducing and sending out new viruses.
疱疹病毒不断复制并释放新的病毒
And that gives the body’s adaptive immune system —
这就让人体后天免疫系统
the one that develops antibodies
能生成抗体
that can bind to viral molecules, or antigens —
用以与病毒或者说抗原结合
a chance to recognize those viral particles.
有了识别疱疹病毒颗粒的机会
But herpes puts the brakes on this process, too.
但疱疹病毒也有应对招数
Normally, there are specialized cells that grab bits of viral antigens
通常 会有专门的细胞捕获一点病毒抗原
and show them to the immune system, like molecular snitches.
然后像分子告密者一样把它们带到免疫系统面前
But herpes gums up the cellular machinery
但是疱疹病毒会给细胞机器使坏
that would normally move antigens into position
让它没法正常捕获抗原
for the immune system to recognize it.
免疫系统也就无法识别病毒了
Still, the host does eventually develop antibodies.
虽然宿主最终还是会产生抗体
Only by this time, it is too late.
但这时 已经为时已晚
The antibodies can’t clear the infection
抗体无法清除感染
because herpes virus is already hunkered down inside the host’s cells.
因为疱疹病毒已经在宿主细胞内休眠了
This is called the latent phase.
这一时期叫作潜伏期
The virus packs up its genome in a tight, circular form,
病毒将其基因组包装成紧密的环型结构
and only certain parts of it continue to be expressed.
只留其中特定的基因继续得到表达
For this to work,
这招要想奏效
the cell it’s using as a secret hideaway has to stay alive.
病毒潜藏的细胞必须保持活性
So the viruses typically target types of cells
所以病毒一般会选择
that last a long time and perform critical functions,
寿命长且作用大的细胞
like neurons and immune cells.
比如神经细胞 免疫细胞
The body is a lot less likely to sacrifice those just to kill off a virus.
人体不大会为了消灭一个病毒牺牲它们
Then, herpes basically hangs out. Forever.
这样 疱疹病毒就能一直待在人体内
Or at least, until the virus determines
至少待到病毒认为情况安全
that it’s safe to re-enter the lytic phase and reproduce —
可以再次进入裂解期 开始繁殖
at which point, congratulations on your new cold sore.
那此时 倒霉的你嘴边又会出现疱疹了
But it turns out, in a lot of people, herpes may be…
但疱疹病毒在很多人体内
more of a frenemy than an outright foe.
其实更像一位友敌而非彻头彻尾的仇敌
Herpesviruses certainly cause their fair share of problems.
当然 疱疹病毒确实会引发相当一大部分疾病
The infections can be severe for immunocompromised people,
它们会让免疫低下的人群出现严重感染
and they’re a leading cause of blindness worldwide.
也是全球主要的致盲祸首
They can also cause some cancers.
疱疹病毒也会引发一些癌症
But for the most part,
但大多数情况下
herpesviruses have evolved to keep their hosts alive and healthy enough
疱疹病毒已经学会了让宿主健康地活着
to interact with others and infect new hosts.
这样他们就能接触别人 病毒就又能感染新宿主
Chickenpox blisters and cold sores are the exception —
除了水痘和唇疱疹
many herpesvirus infections are mild or totally asymptomatic.
很多疱疹病毒的感染症状轻微 或者无症状
Like, by the time we hit 35 years old,
大多数人到35岁
most of us have been infected with the herpesvirus known as Epstein-Barr.
就已经感染上了EB病毒
And most of those who are infected have no idea.
但大部分人都不知道自己被感染了
That’s right: EBV causes most cases of mono,
这很正常 大多单核细胞增多症都是EB病毒造成的
but that miserable sore throat and fatigue
但大多数人都不会出现
doesn’t happen to most people who get it.
让人难受的咽痛和乏力的症状
Lucky them.
幸运的人啊
And weirdly, having herpes hanging out
奇怪的是 体内如果有疱疹病毒
might actually benefit our immune systems.
可能对免疫系统来说是个好事
But that’s a story for another episode.
不过这是我们另一集要讨论的问题了
In the meantime, if you had chickenpox as a youngster,
如果你小时候得过水痘
at least now you know:
至少你现在知道
you had the privilege of hosting one of the most talented viruses around.
你很荣幸 成了这等天才病毒的宿主
Thank you for watching this episode of SciShow.
感谢你收看本集《科学秀》
Much like a herpesvirus infection,
我们的赞助人就像疱疹病毒感染
our patrons stick with us through thick and thin.
风雨同舟 不离不弃
You’re always there for us,
一直都在
and you come out in even more strength when things get bad.
时有不顺 你们的力量愈盛
You help us make videos for everybody,
在你们的支持下 不论贫富
even those who cannot pay for them.
每个人都能看到我们的视频
We love you, even though we just compared you to herpes.
虽然刚才把你们比作疱疹病毒 但我们爱你们
If you want to get involved and help support what we do here,
如果你也想支持我们 出一份力
check out patreon.com/scishow.
那就去patreon.com/scishow吧

发表评论

译制信息
视频概述

疱疹病毒能够突破人体的一道道防线,与人体长期共存。

听录译者

收集自网络

翻译译者

KJQWXYZC

审核员

审核员LAMB

视频来源

https://www.youtube.com/watch?v=FTw6vE-xSwY

相关推荐