How CRISPR lets us edit our DNA | Jennifer Doudna

翻译人员: 易帆 余 校对人员: TIANYU WANG

几年前，

A few years ago,

with my colleague, Emmanuelle Charpentier,

我跟同事Emmanuelle Charpentier

I invented a new technology for editing genomes.

发明了一个可以编辑基因组的新技术。

它叫做 "CRISPR-Cas9" 。

It's called CRISPR-Cas9.

The CRISPR technology allows scientists to make changes

CRISPR技术让科学家

to the DNA in cells

可以改变细胞里的DNA，

that could allow us to cure genetic disease.

从而让我们能够治愈基因疾病。

你可能有兴趣想知道，

You might be interested to know

that the CRISPR technology came about through a basic research project

CRISPR技术其实来自于 一个基础的科学研究，

that was aimed at discovering how bacteria fight viral infections.

它的主要目的是了解细菌 如何与病毒感染进行对抗。

细菌必须在它们的环境里对付病毒。

Bacteria have to deal with viruses in their environment,

and we can think about a viral infection like a ticking time bomb --

我们可以这么想， 病毒感染像是个定时炸弹，

a bacterium has only a few minutes to defuse the bomb

细菌在被消灭前，

只有几分钟时间可以拆除炸弹。

before it gets destroyed.

So, many bacteria have in their cells an adaptive immune system called CRISPR,

很多细菌在它们的细胞里有一种 适应力免疫系统叫做 "CRISPR" ，

that allows them to detect viral DNA and destroy it.

它可以使细菌侦测到 病毒DNA并消灭它。

CRISPR系统中，有一部分 是一种叫Cas9的蛋白质，

Part of the CRISPR system is a protein called Cas9,

that's able to seek out, cut and eventually degrade viral DNA

它能够以特殊的方式寻找出、剪断，

最后削弱病毒DNA。

in a specific way.

我们的研究主要是想

And it was through our research

to understand the activity of this protein, Cas9,

了解Cas9蛋白质的活动，

that we realized that we could harness its function

我们意识到可以驾驭它的功能，

as a genetic engineering technology --

把它当做一种基因工程技术——

a way for scientists to delete or insert specific bits of DNA into cells

一种可以让科学家用 难以置信的精准度

来消除或插入特定DNA片段 到细胞中——

with incredible precision --

that would offer opportunities

这项技术提供了一个前所未有的机会，

to do things that really haven't been possible in the past.

让我们可以做到在过去 根本无法完成的事情。

CRISPR技术已经被应用于

The CRISPR technology has already been used

to change the DNA in the cells of mice and monkeys,

改变老鼠和猴子细胞里的DNA，

other organisms as well.

还包括其他有机体。

Chinese scientists showed recently

中国科学家最近发现，

that they could even use the CRISPR technology

他们甚至可以利用CRISPR技术

to change genes in human embryos.

改变人类胚胎里的基因。

And scientists in Philadelphia showed they could use CRISPR

费城的科学家证实， 他们可以利用CRISPR 技术

to remove the DNA of an integrated HIV virus

从一个感染的人类细胞中

移除HIV病毒(人类免疫缺陷病毒 )。

from infected human cells.

The opportunity to do this kind of genome editing

这个充满契机的基因组编辑技术，

also raises various ethical issues that we have to consider,

也引发了各种我们必须 认真思考的道德争议。

because this technology can be employed not only in adult cells,

因为这种技术不仅可以 运用在成人细胞上，

but also in the embryos of organisms,

也可以用在有机体的胚胎上，

including our own species.

包含我们人类自己。

And so, together with my colleagues,

所以，我和同事们呼吁，

I've called for a global conversation about the technology that I co-invented,

要针对这项技术 展开一次全球对话，

so that we can consider all of the ethical and societal implications

思考应该赋予这种技术的

of a technology like this.

道德与社会责任。

What I want to do now is tell you what the CRISPR technology is,

那么现在，我要告诉你们 CRISPR技术是什么、

它可以做什么、

what it can do,

where we are today

目前的发展状况、

and why I think we need to take a prudent path forward

以及我为什么认为我们 需要一个缜密的思路

in the way that we employ this technology.

来运用这项技术。

当病毒感染一个细胞， 它们会插入自身的DNA。

When viruses infect a cell, they inject their DNA.

And in a bacterium,

在一个细菌中，

the CRISPR system allows that DNA to be plucked out of the virus,

CRISPR系统可以把病毒的DNA拔掉，

and inserted in little bits into the chromosome --

并且将其中一小段插入到染色体内——

the DNA of the bacterium.

也就是细菌的DNA。

And these integrated bits of viral DNA get inserted at a site called CRISPR.

而这些成簇的病毒DNA会被插入到 一个名为CRISPR的位点。

CRISPR stands for clustered regularly interspaced short palindromic repeats.

CRISPR意思是 "规律成簇的间隔短回文重复"。

(笑声)

(Laughter)

很绕口——这回你们就知道为什么 我们要使用CRISPR的缩写了。

A big mouthful -- you can see why we use the acronym CRISPR.

It's a mechanism that allows cells to record, over time,

CRISPR是一种机制—— 它允许细胞随时纪录

the viruses they have been exposed to.

被感染到的病毒。

And importantly, those bits of DNA are passed on to the cells' progeny,

而且重要的是，这些片段DNA 会遗传到细胞的后代，

so cells are protected from viruses not only in one generation,

所以细胞不只有一代会 一直被保护不受病毒感染，

but over many generations of cells.

好几代的细胞都会如此。

This allows the cells to keep a record of infection,

这允许细胞持有受感染的纪录，

and as my colleague, Blake Wiedenheft, likes to say,

就像我同事Blake Wiedenheft喜欢说的，

the CRISPR locus is effectively a genetic vaccination card in cells.

CRISPR的基因座其实上就是 细胞的一张基因疫苗接种卡。

Once those bits of DNA have been inserted into the bacterial chromosome,

一旦这些片段DNA被插入到 细菌染色体内，

the cell then makes a little copy of a molecule called RNA,

细胞就会复制出 一小段叫RNA的分子，

which is orange in this picture,

就是照片上的橘色的部分，

that is an exact replicate of the viral DNA.

它就是病毒DNA的复制品。

RNA is a chemical cousin of DNA,

RNA相当于DNA的化学表亲，

and it allows interaction with DNA molecules

能够与DNA上

相同序列的分子产生反应。

that have a matching sequence.

So those little bits of RNA from the CRISPR locus

所以这些从CRISPR 基因座 转录的RNA片段，

associate -- they bind -- to protein called Cas9,

会与一种叫Cas9的蛋白质相结合，

也就是照片上白色的部分，

which is white in the picture,

and form a complex that functions like a sentinel in the cell.

这个蛋白质综合体像是细胞的卫兵。

It searches through all of the DNA in the cell,

它会搜寻细胞里所有的DNA，

to find sites that match the sequences in the bound RNAs.

找到符合所结合的RNA序列的位点。

And when those sites are found --

当这些位置被找到后——

as you can see here, the blue molecule is DNA --

就是你们看到的蓝色DNA分子，

this complex associates with that DNA

这个综合体会与DNA结合，

and allows the Cas9 cleaver to cut up the viral DNA.

并允许 Cas9蛋白质像刀一样 切断病毒DNA。

It makes a very precise break.

这是一次非常精确的截断。

So we can think of the Cas9 RNA sentinel complex

所以我们可以把Cas9 RNA标记复合体

like a pair of scissors that can cut DNA --

想像成是一把DNA剪刀——

it makes a double-stranded break in the DNA helix.

它在DNA螺旋结构中， 制造了一种"双股螺旋断裂"。

And importantly, this complex is programmable,

最重要的是， 这种复合体是可程式化的，

so it can be programmed to recognize particular DNA sequences,

在程式化后可以用来 辨认特定的DNA序列，

and make a break in the DNA at that site.

并且在DNA的特定位置 制造一个断裂。

As I'm going to tell you now,

我现在想要告诉大家，

we recognized that that activity could be harnessed for genome engineering,

我们已经意识到这个技术， 可以被利用于基因工程中，

to allow cells to make a very precise change to the DNA

就在我提到过的断裂处 使细胞内的DNA

at the site where this break was introduced.

产生一个非常精准的变化。

That's sort of analogous

这个方式有点类似于

to the way that we use a word-processing program

我们使用文字处理软件

to fix a typo in a document.

在一个文档中修改错字一样。

The reason we envisioned using the CRISPR system for genome engineering

我们意识到CRISPR系统 可以被用于基因组工程的原因是，

is because cells have the ability to detect broken DNA

细胞具有检测损坏的DNA，

并修复它的能力。

and repair it.

So when a plant or an animal cell detects a double-stranded break in its DNA,

所以当一个植物或动物细胞在 它的DNA中检测到双股螺旋断裂时，

it can fix that break,

它可以修复这种断裂，

either by pasting together the ends of the broken DNA

把破裂的DNA尾端接合在一起，

with a little, tiny change in the sequence of that position,

只在那个位置的序列产生微小的变化，

or it can repair the break by integrating a new piece of DNA at the site of the cut.

或者，也可以借由在该位置处 聚集新的DNA片段来修复断裂。

所以如果我们有一种方式 可以引导 "双股螺旋断裂"

So if we have a way to introduce double-stranded breaks into DNA

at precise places,

精准地进入DNA，

we can trigger cells to repair those breaks,

我们就可以刺激细胞来 修复这些断裂，

by either the disruption or incorporation of new genetic information.

通过破坏或合并新的遗传信息。

So if we were able to program the CRISPR technology

所以如果我们可以 程式化CRISPR技术

to make a break in DNA

在DNA里制造断裂，

at the position at or near a mutation causing cystic fibrosis, for example,

例如，在囊性纤维化发生突变的 位置处或附近制造断裂，

we could trigger cells to repair that mutation.

我们就可以刺激细胞去修复那个突变。

Genome engineering is actually not new, it's been in development since the 1970s.

基因工程并不是什么新技术， 它在1970年代就发展起来了。

We've had technologies for sequencing DNA,

我们已经拥有DNA测序技术，

for copying DNA,

DNA复制技术，

and even for manipulating DNA.

甚至DNA修改技术。

And these technologies were very promising,

这些技术前程无量，

but the problem was that they were either inefficient,

但问题是它们要么效率不高，

or they were difficult enough to use

要么操作太复杂，

that most scientists had not adopted them for use in their own laboratories,

所以大部分科学家们并不在 实验室采用这项技术，

or certainly for many clinical applications.

或是应用于临床。

So, the opportunity to take a technology like CRISPR and utilize it has appeal,

而CRISPR的技术相对简单，

所以使用它的机会已展露曙光。

because of its relative simplicity.

We can think of older genome engineering technologies

我们可以想像一下 旧的基因工程技术

as similar to having to rewire your computer

就好比每次你要安装新的软件，

each time you want to run a new piece of software,

就要把电脑升级一次一样。

whereas the CRISPR technology is like software for the genome,

而CRISPR技术就像基因组的软件，

we can program it easily, using these little bits of RNA.

利用这些RNA小片段， 我们可以简单地编辑它。

So once a double-stranded break is made in DNA,

那么一旦双股螺旋断裂在DNA中发生，

we can induce repair,

我们就可以诱导修复，

and thereby potentially achieve astounding things,

由此有可能达到惊人的效果，

like being able to correct mutations that cause sickle cell anemia

比如, 能够修正引起镰刀细胞贫血症，

or cause Huntington's Disease.

或引起亨廷顿氏病的突变。

I actually think that the first applications of the CRISPR technology

我认为CRISPR技术的第一项应用

are going to happen in the blood,

会在血液里发生，

where it's relatively easier to deliver this tool into cells,

相对于坚硬组织而言,

更能简单地在细胞内导入这项技术。

compared to solid tissues.

Right now, a lot of the work that's going on

目前, 很多工作已经运用在

applies to animal models of human disease, such as mice.

人类疾病的动物模型中，例如，老鼠。

The technology is being used to make very precise changes

这技术已经被用来 实现非常精准的改变，

that allow us to study the way that these changes in the cell's DNA

使我们能够研究细胞DNA里的变化，

affect either a tissue or, in this case, an entire organism.

不论是对一个组织或 像这个案例中的, 整个有机体。

Now in this example,

在这个案例中，

the CRISPR technology was used to disrupt a gene

借由在DNA里的小改变，

by making a tiny change in the DNA

CRISPR技术被用来扰乱

in a gene that is responsible for the black coat color of these mice.

关联这些老鼠黑色皮肤的基因。

想像一下, 这些白色的老鼠 与它们有色小同伴不同的原因，

Imagine that these white mice differ from their pigmented litter-mates

by just a tiny change at one gene in the entire genome,

仅是由于在整个基因组中的 一个小改变，

and they're otherwise completely normal.

除此之外, 它们几乎一模一样。

And when we sequence the DNA from these animals,

当我们对这些动物的基因做测序，

we find that the change in the DNA

我们发现了在基因里的变化

has occurred at exactly the place where we induced it,

就精准地发生在我们

using the CRISPR technology.

使用CRISPR技术的地方。

Additional experiments are going on in other animals

更多的实验也正在 其它动物身上进行中，

that are useful for creating models for human disease,

被当做人类疾病的的试验模型,

such as monkeys.

像是猴子。

And here we find that we can use these systems

我们在此发现, 我们可以使用这系统

to test the application of this technology in particular tissues,

在特定组织中运用这项技术，

for example, figuring out how to deliver the CRISPR tool into cells.

例如, 如何传送CRISPR工具到细胞中。

We also want to understand better

我们也想进一步了解

how to control the way that DNA is repaired after it's cut,

如何控制DNA在切断后的修复方式，

and also to figure out how to control and limit any kind of off-target,

也更想知道如何控制并限制 任何一种偏离目标的状况，

or unintended effects of using the technology.

或者使用这技术时的副作用。

I think that we will see clinical application of this technology,

我想我们会在十年内就看到

certainly in adults,

它在临床上的应用，

特别是在成人身上。

within the next 10 years.

I think that it's likely that we will see clinical trials

我认为在这段期间， 我们很可能会看到临床试验，

and possibly even approved therapies within that time,

甚至也有可能是 获得批准的治疗方式，

which is a very exciting thing to think about.

想想的确是件令人兴奋的事。

And because of the excitement around this technology,

另外，因为这项技术的兴起，

there's a lot of interest in start-up companies

也涌现了很多初创公司，

that have been founded to commercialize the CRISPR technology,

致力于CRISPR技术的商业化，

and lots of venture capitalists

也有很多风险投资家

that have been investing in these companies.

开始为这些公司投资。

但我们也必须要思考一件事，

But we have to also consider

that the CRISPR technology can be used for things like enhancement.

就是CRISPR技术能被 用在强化性能上。

Imagine that we could try to engineer humans

想像一下我们可以尝试设计制造人类，

that have enhanced properties, such as stronger bones,

像是拥有更强壮的骨骼，

或降低心血管疾病的诱发机率，

or less susceptibility to cardiovascular disease

or even to have properties

甚至拥有我们

that we would consider maybe to be desirable,

期待已久的特征，

like a different eye color or to be taller, things like that.

像是不同的眼睛颜色, 或长得更高。

"Designer humans," if you will.

"订制人"，你们也可以这么理解。

Right now, the genetic information

目前为止，关于哪些类型的基因

to understand what types of genes would give rise to these traits

会有这些特征，相关的基因信息

is mostly not known.

大部分仍是未知的。

But it's important to know

但了解CRISPR技术提供了我们一个

that the CRISPR technology gives us a tool to make such changes,

可以改变现状的工具是很重要的，

once that knowledge becomes available.

尤其是当我们获得了 这些基因信息之后。

This raises a number of ethical questions that we have to carefully consider,

这会引发一系列我们 必须仔细考量的道德问题，

and this is why I and my colleagues have called for a global pause

这也是为什么我跟我的同事们 想要呼吁全世界暂缓

任何临床上有关CRISPR在 人类胚胎上的应用，

in any clinical application of the CRISPR technology in human embryos,

to give us time

给我们一些时间，

to really consider all of the various implications of doing so.

让我们认真思考 各种不同的CRISPR应用。

And actually, there is an important precedent for such a pause

实际上，在1970年代，

有一个类似这样暂缓的重要例子，

from the 1970s,

when scientists got together

当时科学家们聚集在一起，

to call for a moratorium on the use of molecular cloning,

呼吁暂缓使用 "分子克隆"，

until the safety of that technology could be tested carefully and validated.

直到那个技术可以 安全地被小心测试并验证。

So, genome-engineered humans are not with us yet,

虽然经过基因工程改造的人类 还尚未出现，

but this is no longer science fiction.

但这已经不仅仅是科幻小说了。

Genome-engineered animals and plants are happening right now.

动物及植物的基因改造 正在进行中。

这也使我们每一个人都 面临一项重大责任，

And this puts in front of all of us a huge responsibility,

to consider carefully both the unintended consequences

来认真思考这个科技突破 可能会带来的

as well as the intended impacts of a scientific breakthrough.

未知后果和可预见的冲击。

Thank you.

谢谢各位!

(Applause)

(掌声)

(Applause ends)

(掌声结束)

Bruno Giussani: Jennifer, this is a technology with huge consequences,

Bruno Giussani (BG)：詹妮弗 ， 这是个具有很大影响力的技术，

as you pointed out.

你刚才说过了。

Your attitude about asking for a pause or a moratorium or a quarantine

你要求暂停、延期或隔离的态度

is incredibly responsible.

是非常负责任的。

There are, of course, the therapeutic results of this,

当然有一些应用会有疗效，

but then there are the un-therapeutic ones

但也有一些非治疗性的，

and they seem to be the ones gaining traction,

而它们似乎

particularly in the media.

特别受媒体的关注。

This is one of the latest issues of The Economist -- "Editing humanity."

这是经济学人杂志最新的议题—— "定制人类"。

It's all about genetic enhancement, it's not about therapeutics.

关注点几乎都在基因学性能的提升， 而非治疗。

What kind of reactions did you get back in March

今年三月你跟你在科学界的同事，

from your colleagues in the science world,

对此技术提出要求

when you asked or suggested

并建议——

that we should actually pause this for a moment and think about it?

" 我们必须立刻停止并思考 "后， 你们得到了什么样的回应呢?

詹妮弗 道娜 (JD) ：我想， 我的同事们实际上很高兴

Jennifer Doudna: My colleagues were actually, I think, delighted

to have the opportunity to discuss this openly.

有这个机会可以公开讨论这件事。

It's interesting that as I talk to people,

向大众介绍这项技术 是个很有趣的经历，

my scientific colleagues as well as others,

和同事或者其他人说起也是这样，

there's a wide variety of viewpoints about this.

关于这件事大家都有不同的见解。

So clearly it's a topic that needs careful consideration and discussion.

所以很明显， 这件事需要人们进行深入思考和讨论。

BG: There's a big meeting happening in December

BG：今年12月还有一次大型会议，

that you and your colleagues are calling,

你跟你同事都有被邀请，

与国家科学院及其他机构的 专家一起开会，

together with the National Academy of Sciences and others,

what do you hope will come out of the meeting, practically?

你希望会议中能达成什么共识呢?

JD: Well, I hope that we can air the views

JD：我希望我们可以与很多 不同的私人机构及投资人

of many different individuals and stakeholders

针对如何负责任地使用此项技术

who want to think about how to use this technology responsibly.

做一次线上会议沟通。

It may not be possible to come up with a consensus point of view,

也许不太可能会达成共识，

但我认为我们至少要了解

but I think we should at least understand

当我们继续前进时会面临哪些问题。

what all the issues are as we go forward.

BG：你的同事，比方说

BG: Now, colleagues of yours,

like George Church, for example, at Harvard,

哈佛大学的George Church，

他们会说 "对啊，有关道德上的考量， 基本上只是安全性问题，

they say, "Yeah, ethical issues basically are just a question of safety.

我们会不断地在实验室里 做动物实验，

We test and test and test again, in animals and in labs,

and then once we feel it's safe enough, we move on to humans."

一旦我们感觉它够安全， 才会在人体中做测试啊!"

So that's kind of the other school of thought,

所以这有点像其他一类想法，

that we should actually use this opportunity and really go for it.

" 我们应该利用此机会并大胆尝试。"

Is there a possible split happening in the science community about this?

这有没有可能在科学界产生分歧呢?

I mean, are we going to see some people holding back

我的意思是，有些人忍住了，

because they have ethical concerns,

因为他们有道德方面的顾虑，

and some others just going forward

有些人则没有，依然我行我素，

because some countries under-regulate or don't regulate at all?

因为有些国家有管制， 而有些则完全没有？

JD: Well, I think with any new technology, especially something like this,

JD：我想对很多新科技， 尤其类似这样的技术，

there are going to be a variety of viewpoints,

大家都会有不同的观点，

and I think that's perfectly understandable.

这完全可以理解。

I think that in the end,

我想到最后，

this technology will be used for human genome engineering,

这项技术会被用在人类基因工程上，

but I think to do that without careful consideration and discussion

但我认为如果没有深思熟虑并讨论

of the risks and potential complications

其中的风险和可能的并发症，

would not be responsible.

那是不负责任的表现。

BG: There are a lot of technologies and other fields of science

BG：我想有很多技术和 其他领域的科学

跟你的很像，正在急速地发展着。

that are developing exponentially, pretty much like yours.

I'm thinking about artificial intelligence, autonomous robots and so on.

比如说人工智能、自主性机器人等等...

似乎没有人 ——

No one seems --

aside from autonomous warfare robots --

除了自主作战机器人—— 在这些领域中，

nobody seems to have launched a similar discussion in those fields,

似乎没有人发表相同的言论，

in calling for a moratorium.

要来呼吁暂缓之类的。

Do you think that your discussion may serve as a blueprint for other fields?

你是否认为你的讨论也许可以 成为其他领域的参考蓝图？

JD: Well, I think it's hard for scientists to get out of the laboratory.

JD： 我认为，要让科学家 不做实验是不太可能的。

Speaking for myself,

就我自己而言，

it's a little bit uncomfortable to do that.

这样做有点不太舒服。

But I do think that being involved in the genesis of this

但我的确认为我们涉及到 这件事的源头，

really puts me and my colleagues in a position of responsibility.

使我跟同事们必须站出来 为这件事负责。

And I would say that I certainly hope that other technologies

我要说我肯定希望其他的科学技术

will be considered in the same way,

也能用同样的方式来思考，

just as we would want to consider something that could have implications

正如我们考量到某些事 也有可能会牵连到

in other fields besides biology.

除开生物学之外的其他领域。

BG: Jennifer, thanks for coming to TED.

BG：詹妮弗，感谢你来TED演讲。

JD: Thank you.

JD：谢谢。

(鼓掌)

(Applause)