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  • A few years ago,


  • with my colleague, Emmanuelle Charpentier,


  • I invented a new technology for editing genomes.

    ゲノムを編集する新しい技術を 共同開発しました

  • It's called CRISPR-Cas9.


  • The CRISPR technology allows scientists to make changes


  • to the DNA in cells


  • that could allow us to cure genetic disease.


  • You might be interested to know


  • that the CRISPR technology came about through a basic research project

    CRISPR技術は 細菌がウイルス感染と戦う仕組みを調べる

  • that was aimed at discovering how bacteria fight viral infections.

    基礎研究の過程で 生まれたものでした

  • Bacteria have to deal with viruses in their environment,

    細菌はウイルスがいる環境に 対処しなければなりません

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

    ウイルス感染とは チクタク動く時限爆弾のようなもの

  • a bacterium has only a few minutes to defuse the bomb

    つまり 細菌は起爆までの数分間で

  • before it gets destroyed.


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

    そのため 細菌の多くは細胞内に CRISPRという一種の適応的な免疫機構があり

  • that allows them to detect viral DNA and destroy it.

    外来侵入性のウイルスDNAを 検出し破壊します

  • Part of the CRISPR system is a protein called Cas9,

    CRISPRシステムの構成要素には Cas9タンパクがあり

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

    それが固有の方法で ウイルスDNAを検出し

  • in a specific way.


  • And it was through our research


  • to understand the activity of this protein, Cas9,


  • that we realized that we could harness its function


  • as a genetic engineering technology --


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


  • with incredible precision --

    驚くほど正確に削除・ 挿入することで

  • that would offer opportunities


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


  • The CRISPR technology has already been used


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


  • other organisms as well.


  • Chinese scientists showed recently


  • that they could even use the CRISPR technology


  • to change genes in human embryos.

    ヒトの胚の遺伝子さえ 改変できることを示しました

  • And scientists in Philadelphia showed they could use CRISPR


  • to remove the DNA of an integrated HIV virus

    HIVウイルスに感染した ヒトの細胞から

  • from infected human cells.

    組み込まれたHIVのDNAを 除去できることを示しました

  • The opportunity to do this kind of genome editing


  • also raises various ethical issues that we have to consider,

    考えなければならない 様々な倫理的な問題も出てきます

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

    なぜなら この技術は 大人の細胞だけでなく

  • but also in the embryos of organisms,


  • including our own species.


  • And so, together with my colleagues,

    そこで 同僚と一緒に

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

    共同開発した技術について 世界規模の話し合いを呼びかけ

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

    この技術がもたらす 倫理的・社会的影響について

  • of a technology like this.


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

    だからこそ CRISPR技術とは何か

  • what it can do,


  • where we are today


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

    そして 実用化の前に 検討を重ねるべきだと思う理由について

  • in the way that we employ this technology.


  • When viruses infect a cell, they inject their DNA.

    ウイルスが細胞を感染させるとき そのDNAを注入します

  • And in a bacterium,

    そして 細菌内では

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

    CRISPRシステムで DNAがウイルスから取り出され

  • and inserted in little bits into the chromosome --


  • the DNA of the bacterium.

    つまり 細菌のDNAに挿入されます

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

    CRISPRとはウイルスのDNA断片を 挿入する座位であり

  • CRISPR stands for clustered regularly interspaced short palindromic repeats.

    「規則的にスペーサーが入った 短回文型配列の反復群」という意味の略語です

  • (Laughter)


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

    言いにくいですね だからCRISPR と呼ぶのです

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

    これは 感染したウイルスを 細胞が時間をかけて

  • the viruses they have been exposed to.


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

    重要なのは DNA断片の情報は 後世の細胞に引き継がれるので

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

    1世代だけでなく 何世代にも渡り

  • but over many generations of cells.


  • This allows the cells to keep a record of infection,

    このようにして 感染が記録されます

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


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

    CRISPRの座位は細胞における 遺伝子的なワクチンといえるでしょう

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

    DNA断片が 細菌の染色体に挿入されると

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

    細胞は転写により RNAという分子を生成します

  • which is orange in this picture,


  • that is an exact replicate of the viral DNA.


  • RNA is a chemical cousin of DNA,

    RNAはDNAの 化学的な従兄弟のようなもので

  • and it allows interaction with DNA molecules


  • that have a matching sequence.


  • So those little bits of RNA from the CRISPR locus


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


  • which is white in the picture,


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

    これらは細胞内の監視役的な 複合体を作り

  • It searches through all of the DNA in the cell,


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

    複合体内のRNA配列と 一致する部位を探します

  • And when those sites are found --


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


  • this complex associates with that DNA


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

    次にCas9がウイルスDNAを 切断します

  • It makes a very precise break.


  • So we can think of the Cas9 RNA sentinel complex

    ですから監視役のCas9 RNA複合体は

  • like a pair of scissors that can cut DNA --

    DNAを切断できる ハサミと捉えることができます

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

    Cas9はらせん構造を持った DNAの二本鎖を切断します

  • And importantly, this complex is programmable,

    重要なのは 複合体はプログラム可能なのです

  • so it can be programmed to recognize particular DNA sequences,

    特定のDNA配列を認識するよう プログラムし

  • and make a break in the DNA at that site.


  • As I'm going to tell you now,


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


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


  • at the site where this break was introduced.

    細胞のDNAを精密に 変更できることです

  • That's sort of analogous


  • to the way that we use a word-processing program


  • to fix a typo in a document.


  • The reason we envisioned using the CRISPR system for genome engineering

    我々がゲノム工学において CRISPRシステムに期待を抱く理由は

  • is because cells have the ability to detect broken DNA


  • and repair it.


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

    植物や動物の細胞は DNA二本鎖切断を検出し

  • it can fix that break,


  • either by pasting together the ends of the broken DNA

    1つの仕組みは DNA切断部分の両末端に

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


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

    別の仕組みは 切断箇所に 新たなDNA断片を挿入するやり方です

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

    DNA二本鎖を正確な場所で 切断することが出来れば

  • at precise places,

    DNA二本鎖を正確な場所で 切断することが出来れば

  • we can trigger cells to repair those breaks,

    細胞による 切断部分の修復を促し

  • by either the disruption or incorporation of new genetic information.

    遺伝子の破壊や 新しい遺伝情報の 組み込みが可能になります

  • So if we were able to program the CRISPR technology


  • to make a break in DNA

    例えば嚢胞性線維症を引き起こす 突然変異が生じた部位か

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

    その近くでDNAを切断するようなことが プログラム化できれば

  • we could trigger cells to repair that mutation.

    細胞による突然変異株の修復を 促すことができるでしょう

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

    ゲノム工学は新しい技術ではなく 1970年代から開発され

  • We've had technologies for sequencing DNA,

    DNAの配列読取り、複写、操作が 可能になりました

  • for copying DNA,

    DNAの配列読取り、複写、操作が 可能になりました

  • and even for manipulating DNA.

    DNAの配列読取り、複写、操作が 可能になりました

  • And these technologies were very promising,


  • but the problem was that they were either inefficient,


  • or they were difficult enough to use

    使い方がとても難しいという 問題がありました

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

    そのため 科学者の多くは 研究では採用することなく

  • or certainly for many clinical applications.

    もちろん臨床に 応用されることも殆どありませんでした

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

    だから 比較的簡単なCRISPR技術は

  • because of its relative simplicity.


  • We can think of older genome engineering technologies


  • as similar to having to rewire your computer


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


  • whereas the CRISPR technology is like software for the genome,

    CRISPR技術とは ゲノムのためのソフトのようなものです

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

    RNA断片を使って 簡単にプログラムできます

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


  • we can induce repair,


  • and thereby potentially achieve astounding things,


  • like being able to correct mutations that cause sickle cell anemia

    例えば鎌状赤血球貧血や ハンチントン病を起こす突然変異を

  • or cause Huntington's Disease.


  • I actually think that the first applications of the CRISPR technology

    実際 私はCRISPR技術が 最初に使われるのは

  • are going to happen in the blood,


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

    固体状の組織に比べ このようなツールが

  • compared to solid tissues.


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

    現在 ヒトの疾患の研究のための

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

    ラットなどの実験動物を用いた 実験が繰り返し行われています

  • The technology is being used to make very precise changes

    この技術によって 改変が正確にできるので

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

    このようなDNAの改変が 一組織や生物全体に

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

    どのような影響を与えるのかを 研究することができます

  • Now in this example,

    例えば この例では

  • the CRISPR technology was used to disrupt a gene

    CRISPR技術を使って マウスの毛を黒くする遺伝子の

  • by making a tiny change in the DNA


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


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

    これらの白いマウスが 色の付いたひと腹の兄弟と異なるのは

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

    ゲノムの中の遺伝子の1つを 僅かに変化させたからですが

  • and they're otherwise completely normal.


  • And when we sequence the DNA from these animals,


  • we find that the change in the DNA


  • has occurred at exactly the place where we induced it,

    DNAの改変を誘導した まさに その部位が

  • using the CRISPR technology.


  • Additional experiments are going on in other animals


  • that are useful for creating models for human disease,

    人間の疾患モデルの作成に 役立っています

  • such as monkeys.


  • And here we find that we can use these systems


  • to test the application of this technology in particular tissues,

    特定の組織に対する この技術の適用可能性―

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

    例えばCRISPRツールを細胞に導入する方法の 解明に利用できることがわかりました

  • We also want to understand better

    また もっとよく理解したい点は

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

    切断後のDNAの修復を コントロールする方法や

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

    標的としていない部位への影響を コントール、抑制し

  • or unintended effects of using the technology.

    予期せぬ作用が 起こらないようにする方法です

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


  • certainly in adults,


  • within the next 10 years.


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

    この期間で臨床試験ができる 可能性は高いですし