Into the Future with CRISPR Technology with Jennifer Doudna

[Music] thank you for joining us tonight for the Nuremberg Prize for science in the public interest this is one of my favorite events during the year because it's a chance for us to bring really the best and brightest from the science community so it's really a pleasure to welcome you to this event this event is made possible every year by the generosity of the Nuremberg family the prize was established by the Nuremberg in honor of a bill Nuremberg who was a former director of Scripps he was longest-serving director of Scripps oceanography and our my thanks as well as those of the entire scripps community go out to the Nuremberg family thank you again for making this possible and you bring us so much scientific delight every year it's really a pleasure so it's now my pleasure to welcome to the podium dr. Walter Schinkel Bill's son-in-law and Walter is the Robert o Lawton professor at Florida State University which is that university's highest level of distinction for the professorial so with that let me turn to a few remarks on dr. Dodman she is the Chancellor's professor in biomedicine and health at the University of California in Berkeley where she continues and extends her work on several RNA related systems her contributions have been recognized by many awards including as a young researcher the Waterman award and the breakthrough prize and life sciences the Gruber Prize in genetics Canada Gardner international award and the Japan prize dr. Donna was chosen as the 2019 recipient for the reprise for what are among some of the most important advances in the history of Molecular Genetics discoveries that as you will hear promise to revolutionize our understanding of and control of how genes work when dr. Donna and Emanuel sharpen chair is that correct showed in 2012 that enzymes from bacteria that control microbial immunity could be used for precisely editing genomes you can see that it was kind of a final step for not only describing an understanding genes genes but also for altering them in specific ways this makes it one of the most significant discoveries in the history of biology and was completely unimaginable when I was born in 1940 but that's the nature of science this grand enterprise that we call science it has been said and notice I used the passive voice it has been said that 90% of existing scientific knowledge was created during the life of every scientist that has lived in the last 400 years that has certainly been my experience when Professor Doudna retires and whenever she's going to retire she can be satisfied that she has contributed a substantial amount so that 90% so from her Wikipedia page who doesn't use Wikipedia after I learned that during herself in sophomore year she questioned her own ability to pursue a career in science and considered switching her major to French however her French teacher suggested that she stick with science so we owe that French teacher a large debt of gratitude because there is no nirenberg prize for French in the public interest [Applause] it's thus my honor on behalf of the nirenberg family Scripps Institution of Oceanography University of California to present this medal for the Nierenberg Prize for science in the public interest to you it's a real pleasure for me to be here at at Scripps and to to be able to share with you in this kind of celebration of science I want to start by thanking the Nierenberg family it's been a real pleasure to meet all of you this evening and also the the prize selection committee it's a delight to have this opportunity to share with you science that I've been working on over you know the last maybe dozen years or so and to tell you a story that I think really nicely illustrates the the value of fundamental science and curiosity driven research something that I've always valued deeply and for all the students here I really want to communicate to you that I started off you know in sort of very humble beginnings I grew up in a small town on the Island of Hawaii and nobody in my family was a scientist I just you know I loved chemistry and I loved mathematics and I kind of thought I wanted to do something in science I I didn't know any scientists and I certainly didn't know any female scientists so it seemed like kind of an adventure that I was embarking on and I was very lucky that I had along the way a lot of people who were able to kind of steer me in the right direction at the right time including my French teacher so thanks for giving her a shout out and and what I thought I would do tonight is I really want to do two things I want to just share with you a little bit about how we got interested in this area of science and and to show you that my career started off in a very different place from where where I am now where I am today and that's something I love about science it goes in directions that I think none of us can really predict and the other thing I want to share with you as this is a prize about science and the public interest is to discuss what happens sort of my personal experience with being involved in a field that very quickly sort of before any of us kind of could almost get our heads around it was going in directions that we realize we're going to have profound impacts in the future for everyone and having to grapple with that and and think about where we're going with this technology where we as a as a you know as a species are really going with a very powerful tool that allows us to alter the DNA sequences in cells and organisms including in ourselves and really control ultimately evolution in that way it's really a profound thing to think about but where did this all begin and so I thought I would just start by pointing out that you know when I was growing up my dad and my dad was a professor of literature at the University of Hawaii so he read a lot of books and he wasn't a scientist but he liked science books and one day I came home from school and I saw this sitting in my room and so this was really one of the first books that I read about science and if you've read Jim Watson's book the double helix you know that it's a story of the discovery of the structure of DNA but it's also a story about the very human aspects of doing science and I still remember being incredibly surprised to read this book and you know I was used to reading you know kind of dry textbook descriptions of science and this book for the first time kind of made it seem like a very human endeavor with you know people's foibles and and you know just sort of the process of discovery being described in a way that I hadn't been able to imagine before so this really sort of captivated me and I would say in no small way contributed to my interest in applying the study of chemistry to biological systems so now fast forward many years and you know I went off to college and majored in chemistry and then I went to graduate school in biological chemistry and eventually you know through a somewhat circuitous tour ended up at the University of California Berkeley where I started studying the process by which cells are able to control genetic information in cells and one day in the mid-2000s I think I'd been at Berkeley about three years I got a call from Julian Banfield a colleague of ours who told me about a system called CRISPR that at the time almost nobody on the planet had heard about so it was a very very obscure area of study and she was extremely excited about it because her work which was focused on sequencing bacterial DNA hinted that this CRISPR system might be an adaptive immune system in microbes in bacteria a way that bacteria could acquire immunity to viruses that they encountered in the environment well I was I was intrigued and I thought this sounded like something very interesting for somebody like me a biochemist to investigate now part of the reason for that is that I have to tell you a little for those of you that are not maybe not scientists in the audience or not not molecular biologists I have to just remind you that in sort of the fundamental what we call the central dogma in molecular biology is shown right here which is that you know there's sort of this flow of genetic information that controls all of life namely that genetic information is encoded in DNA and what that code does is to tell cells how to make ultimately proteins which are on the far right-hand side and in the middle was this you know as this sort of at least when I was taught this originally in college kind of this very boring molecule called RNA that you know kind of you know DNA is chemical cousin and you know we were kind of taught in college that you know this was just kind of a transfer molecule it's just sort of shuffling information from DNA to proteins and you know don't pay very much attention to it and then when I wonderful thing about you know going off to graduate school was that I was sort of awakened to the idea that in fact in many cases RNA molecules these chemical copies of DNA sequences actually did very interesting things in cells and so I actually my whole career from that point on was really focused around understanding the functions of these RNA molecules what they do and how they fold up into interesting three-dimensional shapes that allow them to do things and in cells that can't really be done by either DNA molecules or proteins well so it turns then in a very interesting way that interest in understanding RNA and its function in biology converged with CRISPR and to understand that I have to show you a little cartoon that illustrates how these adaptive immune systems function in bacteria and by the way this is based on not my research but on work that was done in about five or six laboratories around the world that in the early 2000s we're starting to investigate these CRISPR systems to figure out if they really were functioning to protect bacteria from viruses and so what these handful of scientists figured out is that bacteria so we're looking here at a cartoon of a bacterial cell that's being infected by a virus and when a virus infects a cell whether it's infecting a bacterial cell or or us a human cell what happens is that the virus injects its genetic material shown here sort of wrapped up in this capsid injects it into the cell where it then creates a program a molecular program that starts to make all the molecules required to make more viruses and kill the cell that's really the process of viral infection and so in bacteria if there's a CRISPR system that's encoded in the DNA of this bacteria then the cell is able to detect that foreign DNA that gets injected by the virus and insert a little piece of it into this part of the genome known as the CRISPR locus and this provides a molecular memory of infection that over time grows larger and larger so it keeps a kind of a molecular recording of infections and allows the cell to protect itself in the way that that protection works involves RNA so the cell is able to make an RNA copy of this CRISPR sequence and that RNA is chopped up into units that each include a little squiggly line here that represents a sequence of coming from a virus and that sequence is actually a series of letters it's about 20 letters long letters that match letters in the DNA of the virus and so these RNA molecules combine with proteins encoded by genes sitting next door to the CRISPR locus in the bacterial DNA and these protein RNA assemblies are able to search through the cell looking for matching DNA sequences and if those are found then the cell is able to cut these up and and destroy them so it's a great way that cells can acquire immunity to phage using this RNA guided system so I was very intrigued by this is an RNA biochemist and I really wanted to understand the process of how this works now just to give you a sort of another illustration of the way that bacteria are using CRISPR systems I wanted to show you this video that illustrates how we imagine that CRISPR is operating in the in nature so here's a bacterial cell that's being infected by a virus injecting its DNA and if the cell has a CRISPR sequence in the genome it can acquire a piece of viral DNA into this part of its own DNA and these are flanked by repetitive sequences so it kind of signals to the cell that this is a special part of the genome and when the cell makes an RNA copy of that sequence those molecules those crisper RNAs can be chopped into units that each include a sequence that comes from a different virus these RNAs turn out to combine with a second type of RNA called tracer to form a structure that can interact with a protein known as cast 9 now that cast 9 protein is able to search the cell looking for molecules of DNA that have a sequence matching this crispr RNA sequence and when that match occurs the DNA opens up the cast 9 protein cuts the double helix of DNA and then these cut up pieces of DNA are degraded so that's really how this works in nature and this this again just shows a cartoon of the pathway and and and so at the top we're looking at a virus injecting its DNA here's CRISPR sequence that's getting expanded as a piece of viral DNA gets inserted into the the genome and then here are those RNA molecules generated and combining with Cass proteins to allow recognition and destruction of viral DNA and so for us as biochemists we were fascinated by the question that relates to how this works how does this happen and so I started off studying first of all just sort of this RNA guided process how these RNA molecules were produced and then ultimately focusing on how these RNA guided proteins are able to search the cell find a matching piece of DNA and then what happens next and so this we call this part of the pathway interference and what I found was that so we started working on this in the sort of the late 2000s I think it was around 2006 or so that we started investigating this and initially in my lab most of the members of my lab we're doing something else they were working on other RNA related systems in mammalian cells we weren't actually working on bacteria for anything else in the lab and but over time what happened was that the research was so interesting that the one or two people initially that were working on this in the lab Blake Whedon heft and Rachel har Wits to initial lab members studying this process their work was so interesting that I found that members of my lab kept coming into my office and saying can I work on CRISPR so that's how a project that started off as just a you know kind of a curiosity driven effort turned into something bigger initially and eventually I went to a conference and this was in 2011 I attended a meeting that I normally would have never attended by an organization called the American Society of microbiology so I'm not a microbiologist why did I get invited to this meeting well they had one session on CRISPR biology and because there were you know very few people working on this at the time I prayed I guess I got invited maybe for that reason and so there I was at this meeting and I met other scientists named Immanuel sharp NTA who was coming to CRISPR from a very different background for me she's a microbiologist studying bacteria that infect people and trying to understand fundamental biology about these infectious bacteria for the purpose of ultimately developing good ways to fight them off and so we got together at this conference we decided to go after a question that might sound obscure to you initially it was this question here what is the function of this protein known as cast 9 and the reason that we were interested in this is that Emmanuel's lab had evidence that this protein in the bacterium she was studying had the unique ability to use these CRISPR RNAs to find and somehow destroy viral DNA by molecular mechanism that was unknown at the time and so we both wondered whether this in fact might be some kind of an RNA guided cleaver nobody had tested that but we thought it would be an interesting question and and if it in fact was an RNA guided cleaver was this sort of a little widget that you know bacteria of many different types were ultimately deploying in nature to defend themselves against viruses so it's a it was kind of a fun question and and so that started a wonderful international collaboration emmanuel was located at the University of Omaha in Sweden at the time and so I came back to my group in in Berkeley and I invited a postdoc Martin Janek who was just served in the last year of his training in my lab asked him whether he wanted to work on this project and the timing was perfect and he was the right guy at the right time to work on this on this story because he was a fabulous biochemist I was able to team up with a student at Christian Lenski in Emmanuel's lab to do experiments that would have been very difficult for either lab to do on their own and so what these guys figured out was that this casts nine protein is what we call a dual RNA guided DNA cutting enzyme now what do I mean by that I'm showing you here a cartoon of the cast nine protein so remember that that's being made in bacteria that had a CRISPR system and it's literally a programmable protein and what I mean by that is that it's got a protein it's got a program that is defined by this molecule of RNA called CRISPR RNA that has a twenty letter sequence derived from viruses at least in bacteria that can direct this protein to recognize a piece of DNA that comes from a virus because it has this matching sequence in the DNA and importantly this is a protein that requires a second type of RNA called tracer for assembly of this targeting complex and when this thing searches the cell and finds a twenty letter sequence in DNA matching the crispr RNA it's able to unwind the DNA double helix and allow cast nine to make a break a cut in both strands of the double helix you can think of DNA almost like a rope with with two strands we're winding around each other and this protein is like a cleaver that comes in and cuts the rope and a mark remarkably this isn't happening randomly in the cell it's happening only at a place that matches this guide RNA now when when we did these experiments initially so so Martin Jenek in my lab fabulous biochemist was doing what biochemists do he was figuring out how this works by purifying these molecules and testing their activity under controlled laboratory conditions and that led to the realization that we could actually simplify the system compared to what nature has done where we have to separate molecules of RNA that provide the program forecast line by linking these RNAs together in what we called a single guide RNA format so now we have a molecule that's got the program here and it's got the handle for interaction with cast nine over here now this handle is the same in every RNA molecule but we could trivially change this 20 letter sequence on the other end to direct cast nine to a desired piece of DNA for cutting and Martin did a great experiment where he literally designed five or six different single guide RNAs that allowed us to cleave a piece of DNA at places that we predetermined by simply inserting the desired sequence right here in the RNA and when Martin did that experiment that was for us the aha moment when we looked at each other and said holy smokes this is a programmable protein we know how to control it and we can make it introduce a double-stranded break in DNA at a desired place now why was this yeah and the other thing i like to say is that this is really the moment when for us this project went beyond this kind of little kind of curiosity driven niche question to implicating something much much bigger and to explain that i have to show you what was going on across biology and know many many other labs over the previous two decades which was namely to understand how DNA is repaired in cells and how cells like ours and plant cell if plants sort of plant an animal and human cells handle DNA double-stranded breaks they do they do something different from what bacteria do namely they recognize that when a double-stranded break occurs in DNA instead of allowing this to lead to DNA destruction this actually triggers DNA repair and the repair can involve either a little disruption of the DNA sequence during the process of repair but right at the position of that initial break or it can lead to insertion of a new piece of DNA at the site of that initial break and people had recognized that if you could introduce a break in a genome in the DNA of a cell at a desired position you could trigger an edit to the DNA you could trigger the cell to change the DNA sequence at just that position and nowhere else and the challenge had been in sort of across the field at that time that was called genome Engineering was how do we how do we introduce double-stranded breaks into DMA so that this process can take over and there were earlier technologies for doing this frankly going all the way back to you know in the 1980s when I was a graduate student chemists were figuring out how to introduce double-stranded breaks that could allow mapping of genes and human cells and things like that but those technologies were you know difficult enough to work with that most labs weren't able to adopt them and the wonderful thing about CRISPR is that it's a simple enough system that scientists immediately grasped how powerful this could be and how you know is this sort of simplified this challenge of making a targeted edit to the genome so you heard in Walters wonderful introduction that you know there's been a progression of technologies that have happened over the last few decades that have brought on the sort of the modern era of molecular biology and I think in many ways this technology of genome editing really is the the the was the missing piece it provides scientists with the ability not only to read DNA and and write DNA by synthesizing it but also to rewrite DNA to really edit the code of life for the first time and that's why there's been tremendous excitement about this I want to show you this is a video that just helps you to imagine how this actually works so here we are zooming in to a eukaryotic cell a plant or animal cell where the DNA is inside the nucleus and we're seeing Castine molecules with their RNA program searching through the DNA looking for a matching sequence and when this match occurs this enzyme this protein is able to interact by unwinding the DNA the RNA molecule is able to interact with one strand of the DNA inside the protein and that triggers cleavage so the DNA is cut and then this protein cast 9 is able to hand off the broken ends of the DNA to repair enzymes in the cell that fix this break by processes that include making a small change to the DNA shown here but also sometimes two actually inserting a new piece of genetic information at the site of the break so very quickly after we published this work in the summer of 2012 labs around the world began to adopt this tool for engineering and editing the DNA of in cells and organisms of all types and what was amazing was that it seemed to work robustly in many systems so it wasn't unique to bacteria or even to human cells but to everything else you know plant cells other kinds of single molecule single cell celled organisms but also various other kinds of plants and animals this is a chart that I showed just it's based on one of the academic journal publishing houses that shows what happened in scientific publications with technologies for genome editing so these are technologies for genome editing that preceded CRISPR they're called mega nucleases zinc finger nucleases and talent so these were all different kinds of engineered proteins that could be engineered to recognize and cut DNA at a single site and they you know had a you know a certain impact certainly in the scientific community showing people what was possible with genome editing but when Christopher came along this just took off extremely rapidly really essentially as an exponential curve of growth and we now see thousands of papers in the scientific literature so it really gives you a sense of the pace of science I've certainly never experienced something like that in my scientific career where there was just this you know kind of explosion of science that became suddenly possible once you had a tool that was easy to use or easy enough to use for for genome editing and so what we want to do now is I really want to turn to some of the both the opportunities and I think the important challenges that we face now that we have this powerful technology in hand to edit genomes what are people doing with this how is it going to any of us in in the near future and what do we do about some of the things that might you know concern us about using a tool like this and I wanted to start off so I wanna I want to really touch on four things one is how CRISPR is affecting research sort of fundamental research that you know many of us and many folks here are doing and also how it's a it's going to affect Public Health agriculture and biomedicine and and I would just start off by pointing out and we had a great conversation here earlier today that it really highlights the the little vignette I'll tell you next which is that one of the things that CRISPR has done for science is that it's made it possible to study organisms at a level that was never possible in the past namely that you know in the past you if you wanted to ask a question about the genetics of life and understand the genetics of a pathway you typically had to work in what we call model organisms there were a few sort of handful of these that had been developed very very very studiously and carefully over you know over many years and in labs that allowed scientists to use genetic tools to manipulate DNA but with Chris Berg it suddenly became possible to manipulate the DNA of essentially any type of organism and here's a great little story that illustrates the potential of this so you know one of the long-standing questions in biology has been why is it that organisms and here which I'm showing a snail have handedness to their body type right and so this is you know showing you that you know in in with with snails most snails in nature look like this in fact the vast majority where they're their shells actually curved around to the right and the question was you know what why why is that what are the genetics of this and you know could you actually make a snail with a left-handed shell and this you know sounds like a crazy question but it's actually very interesting because many organisms have handedness to their bodies and and we don't we haven't really understood the genetics of that well here was a case this was actually just published earlier in 2019 where a group was to use the CRISPR technology to go in and manipulate the genetics of these snails to find the gene that's actually responsible for that and create left-handed snails these guys over here and it's you know it's one of these just wonderful examples of a long-standing question that was waiting for the right tool the right technology to come along so that it could actually be answered and there's many really cool examples of this like there's a there's a wonderful woman that's working on the evolution of bipedalism you know why are we why are we able to walk on two legs while she's doing it by studying and comparing rodents that are either quadrupeds they use four legs or they're bipedal and by doing you know genome editing to introduce genes from one end to the other trying to figure out is there a simple program genetically that leads to bipedal isn't you know a question that you could have never imagined being able to answer even a few years ago so what else is going on well this is an example that hits very close to home there's a fabulous project that's going on with Ethan Beyer and his colleagues here at UC San Diego understood understood be used for something called gene drives and the the summary here is really just that you know if we look at how normal inheritance works this shows you that you know if we have a population let's say of mosquitoes they're passing along traits according to Mendelian genetics this is kind of what this would look like so an altered gene doesn't spread very rapidly through a population because it's got to take this this sort of generational progression but imagine that you had a tool that allowed you to very rapidly introduce a genetic trait into organisms that didn't have that trait naturally in their genome and that's really what CRISPR does you can use it in a way that will allow this kind of lateral spread of genetic traits that we call a gene Drive and this means that ultimately the altered gene is almost always inherited and and this is sort of a kind of an interesting trick of I suppose of the technology but it has a very interesting practical implication which is that now it may be possible to control mosquito popula Asians for example by engineering them so they either don't reproduce or that they can't pass along a parasite that would otherwise be spread by mosquito bites so that this could have a potentially very dramatic impact on public health globally so that's something that there's a lot of interest in investigating because of the you know rapid spread of things like dengue virus and Zika etc in agriculture again you know just really interesting opportunities I love showing this slide it's worked by Zack Lippmann a scientist at Cold Spring Harbor labs who is able to use CRISPR to alter the the genetics of tomatoes in a way that produces plants with fruit that's genetically identical to its parent species except that it makes a lot more of these a lot more Tomatoes and I can tell you that from personal experience with CRISPR tomatoes which I just enjoyed with my family in about two days ago these are fabulous they're they're they're they're wonderful tasting fruits but you get about 2 or 3 times more per plant and my son was asking me well why why would that why would that be important mom and it's you know it sort of made us sort of discuss well what if you could produce the same amount of food from a much smaller number of plants imagine how that might impact water use how might how it might impact the need for for various kinds of either pesticides or nutrients that are required for these plants it's it's it's something that I think could have a very big impact globally in agriculture and I personally think that genome editing you know at least in the near term will have its biggest impact on human societies through agricultural applications now this doesn't come without challenges so this is a this is an example of some work that was done in an academic lab at Penn State University so they were able to use CRISPR to knock out a single gene in mushrooms that prevents these mushrooms from turning brown when they're cut open so maybe you've slowed fur you know marketing purposes but it did raise the question of you know how our products like this going to be regulated or are they going to be regulated and this sort of general at headlines a couple of years ago because in the United States but the Department of Agriculture decided that modified plants of that type with that had been changed at genetically using CRISPR were not going to be regulated why not well because the way they did that made that mushroom was to disrupt a gene they didn't introduce a new piece of foreign DNA into the mushroom they simply disrupted a natural gene that was there and so that in the u.s. that plant product would not be considered genetically modified and would not be regulated now that's not true everywhere so in Europe there's a you know active debate about this but but a recent ruling suggested that you know there would be concern about this in Europe and that plant products of that type would in fact have to be regulated and in fact might not even be marketable so this has been a very active area of discussion and lots of companies of course thinking about this because it affects international trade and how agricultural products might be purchased and sold abroad and guaranteed this will you know continue to be very actively debated because people are grappling with you know what does it mean to have a tool that allows rapid manipulation and targeted manipulation of the genetics of plants and then finally before I get into sort of biomedical applications I wanted to mention that there are increasingly we're finding opportunities to use CRISPR cast systems and proteins in ways that might not have been anticipated initially so this was some this is sort of a summary slide that is based on research that two graduate students in our lab Alexandre Issa less key and then Janice Chen did initially showing that in some CRISPR cast enzymes that are related to cast line but but come from different kinds of bacteria they actually have a remarkable ability to recognize a piece of DNA using the RNA guides that's what this cartoon shows but in addition to cutting that target strand of DNA the cutter cutting domain in the protein remains active and can cut pieces of DNA that are provided to it in in sort of in what we call in trans as a separate piece of DNA and and what Janice Chen figured out was that you could actually make little pieces of DNA chemically that have fluorescent dyes associated with them and when those pieces of DNA are cleaved they release a fluorescent signal that you can detect in the lab now why would you want to do that well it turns this CRISPR cast protein into a sensor that when it detects a sequence matching the guide RNA it turns on the cleaver and you get a fluorescent signal so we're now using this as a way to detect DNA molecules in settings where you don't have access to fancy technology and we've found so far that you can do very rapid and very sensitive detection of DNA using both actually both DNA and RNA it turns out using these types of proteins so this is a potentially and interesting strategy in the future for Diagnostics so I finally I wanted I wanted to turn to what's happening in biomedical science by pointing out that when we talk about genome editing it's important to understand that the that the way that cells are edited occurs in two different types or two different flavors one we call somatic cell editing and that means making changes to DNA that ultimately affect fully differentiate or fully developed organs or organisms and are not inherited by future generations and that's different from making changes in germ cells in the germline like you know sperm or eggs or embryos where those genetic changes are inherited by future generations and and so you can just if you start to think about it you can imagine that you know there are very different issues that come along with these two different types of editing for doing somatic cell editing and especially if we were doing this to let's say cure someone of a genetic disease if this were done in an individual I would argue that that technique is essentially not really distinct from at least in terms of its safety and effective it's not really different from other kinds of therapies that you might use you'd want to be sure it worked and you'd want to be sure it was safe but it's affecting that one individual but this is very different right this is making a change that becomes permanent in that person and their children and grandchildren etcetera so it's passed on to many generations and so but I'll come back to that but I want to first illustrate an example of somatic cell editing I have to tell you that this is an area where I think there's tremendous opportunity the field is moving really fast we already have clinical trials that are underway for at least four I think right now for focusing on cancer and eye diseases but in the near future for some other diseases including sickle cell disease now this is a disease of the blood it involves a single letter change a single base pair and DNA that is mutated in patients that have sickle cell disease and if they inherit two copies of this hemoglobin gene that have the sickle mutation then they produce hemoglobin that is prone to aggregation and their blood cells become sick 'old and this is a cartoon that illustrates what happens in that case which is that typically there they have blood vessels that get clogged with these cells and they undergo these horrible sort of sickle crises that happens sort of successively and right now medicine doesn't have any way to cure these folks or even really to treat them except to give them blood transfusions and you know so the given sort of palliative care but it's it's a very you know it's a very unpleasant disease and I wanted to show you a clip from a forthcoming documentary called human nature that takes a look at just to give you a flavor for what its gonna be like when we can actually cure a disease like this you know and we're on the horizon of this and this clip just starts off with showing you a boy called David and his name is David who is sickle cell suffers from sickle cell disease and he goes to Stanford University and he works with a scientist there Matt Porteous to observe how CRISPR could work to correct the disease-causing mutation in his own blood cells so take a look at this so now we're mixing the cells with the CRISPR once it's into the cell not starts the editing process we can't see that we just know it happens I don't know how out of all the genes that you have that it targets the one that's doing sickle cell and not the thing that's making you grow hair oh but it does apparently that's cool and I just think that is so awesome and when you know when I watched this film for the first time and saw that clip it's so moving because you know this boy Emmitt you know if you watch this movie it starts off and that's a documentary it starts off with him in the hospital with his grandmother and he's going through a sickle crisis and you know he's suffering but other than that he's just a he's a very normal teenager you know he's playing basketball and he's got his iPhone and he's and and and it just it gives you a sense that in the future we will be able to offer people like David a cure for this disease that otherwise he would be suffering from for his entire life now um now that would that would involve somatic cell editing okay so this would involve making changes to the cells in one individual's blood since blood supply blood system but not changes that could be inherited but heritable germline genome editing is different that means making changes in eggs or sperm or embryos this is an example of a mouse embryo that's being held over here by a pipette and you can see on the other side a needle coming in and injecting CRISPR cast nine with its guide RNA so this started to be done very early on just in the in the first few months after we had published this work in 2012 Rudolf jaenisch and then many others started to do this in animal cells in fact in sort of mice and rats or animals that are used a lot in scientific research they'd also it's also been done in pigs as I showed the last on the last slide and many other now kinds of organisms so it was clear to many of us from those early moments that of this technology that that there wasn't didn't seem to be any scientific reason why it couldn't also be done in human embryos and what would that mean and what would be the implications of this so in the early 2015 I convened a meeting of scientists up in Northern California we invited people from around the country who had been involved in different capacities with thinking about either new or you know budding technologies and in molecular biology or were active using the crisper cats 9 technology and we ended up writing a perspective that was published in a scientific journal science magazine that it really called for what we we termed a prudent path forward and this is the the purpose of this was really to highlight - not only scientists but we hoped people who were beyond our field of science about the the potential but also the the risk of this technology especially if it were applied in human embryos to create babies who would then have Gino Metz edits that they could transmit to future generations and and this led to various kinds of international meetings including eventually a report that was published in early 2017 by the National Academies of science on this and essentially all of these reports early on called for whether they termed it a moratorium or or something else they were really all calling for a restraint on the scientific community from using this to create gene edited babies but then at the end of 2018 the event that you know many of us sort of could foresee coming at some point actually happened that was that a scientist announced at a conference in Hong Kong that he had in fact created babies had had created human embryos that had gene edits that were then implanted to create a pregnancy and there was the birth of twin girls who had alterations to their genome created using CRISPR now this set off kind of an international outcry I would say I was at this meeting when a junk we shown here was presenting this work and and I think many of us felt that this was just wrong on many levels it was wrong because the science and technology wasn't ready for this kind of application but more importantly it was wrong because there hadn't been an opportunity to really deeply consider whether this would be a wise use of the technology and how would people who had been treated in this way like such as these these girls how would their health be monitored how would we be able to ensure that they wouldn't have and they of health outcome and one of the things that was most shocking to me was actually that that when when this was actually the work of Shawn writer a professor at the University of Massachusetts he actually took the data that ho-chunk we had presented at the conference which by the way has still not been published in a peer-reviewed place and looked in detail at the genetic manipulations that were introduced what was clear was that the changes that were introduced were not those that were actually intended and they had never in fact been tested in humans so just to understand this I you don't have to look at the details at all here but you just need to notice that these two bars at the top don't look like these three on the bottom so the top is a cartoon of a gene called ccr5 that is encodes a protein necessary for HIV virus to infect a person's immune cells and the purpose the stated purpose of this work was to disrupt that gene by creating a 32 base pair deletion of DNA in that ccr5 gene to disrupt the encoded protein and prevents HIV from being able to infect people that would have this this disruption in their in their DNA and in fact there are natural people in the natural human population that that have this kind of disruption and that was one of the tip-offs that ccr5 is an important receptor for HIV viral infection well unfortunately when the CRISPR technology was used in these in these embryos that were implanted it appears that the changes the genetic changes that were made yes they occurred in the ccr5 gene but if you look at the details the details are different from this here so all three of these changes that were found in the these twin girls that were born are different from any change that to anyone's knowledge have ever been naturally occurring in the human population and they've never even been tested in animals so you know it's really was sort of chilling to me to see this presented as it was something desirable to be done now um with that being said you know where we go from here you know our crisper baby just sort of right around the corner and you know and we continue to see stories in the media about this there's there's no doubt that there's a lot of interest in this both from storytellers and people in Hollywood but also from scientists you know and I you you know you might or might not be surprised to know that I've had calls from people in the u.s. very reputable people who are interested in this technology they want to know how soon it will be possible to do this how can they get involved in working on this and you know it's it's clearly something that intrigues many people so you know are these sorts of traits right around the corner well you might or might not be relieved to know that these are all the types of traits that typically involve many genes not just one and in most cases we don't know the collection of genes that lead to these phenotypes so like it or not we're probably not going to be able to you know deal with this genetically any time soon and and and I think that our knowledge of the human genome at least today really holds back the editing of human embryos for for clinical use but that will change over time so I think it's critical that we grapple with this very interesting but very challenging question and an application of gene editing right now so what's happening well you know the World Health Organization has a has convened an international committee to review this and that's also going on in a committee that's convened by the National Academies of science their reports will be coming out in the coming months and in the meantime you know many of us are you know in the scientific and clinical communities are actively debating and discussing this at the innovative genomics Institute that I run up in the Bay Area we have a sort of an ongoing public lecture series where we invite people to come and learn about the technology and discuss and debate this this this topic as well as other applications of CRISPR and I think that's that's really gonna be key to ensuring responsible use going forward so I just want to close by pointing out that you know the what I showed you sort of this RNA guided mechanism of gene editing but I would call it really gene regulation I didn't have time to show you but there's sort of many ways to manipulate the CRISPR tool so that you can control the levels of proteins that are made from genes this is a really powerful technology it's a whole toolbox that scientists now have for controlling genetics in essentially any type of organism it's going to be essential to figure out how to deliver these molecules into cells and tissues certainly for clinical use and also to control the way that genome editing happens as you saw on that example with the ccr5 gene and finally fundamental research continues so scientists globally are continuing to find new examples of these systems to engineer them to do things they don't do in nature and and I really feel like we're you know we're really sort of right living right in the midst of this transformative technology that is going to change our world and it will change it in the very near future so I want to thank a great team so this is a group some of my lab members up at Berkeley and we've had many great collaborators over the years I'm just showing a few of them here I particularly want to shout out Manuel sharp MTA with whom we started this work on CRISPR Castine and she's now located at the Max Planck Institute in Berlin and then you know aside is academic scientists we rely on public and private funding for the work that we do and I really want to thank all of our funding sources and in particular the Howard Hughes Medical Institute and the National Science Foundation they both gave my lab money to work on CRISPR biology back at a time when you know none of us had any idea where it was going and so I'm really grateful for that and finally I'll just mention the innovative genomics Institute where you can find us on the web and we're really an organization we're academic we're nonprofit we're interested in advancing genome research but doing it with sort of social responsibility in different ways guess out on the web and if you come to the Bay Area I'd be delighted to hook you up with a with a tour thank you very much it's a great question he's asking about the patent situation so if you haven't if you aren't aware of it you know CRISPR babies are one topic the media loves to write about and the patent fight over CRISPR is the other so you know this is a it's a very interesting situation I would say because the question fundamentally is what happens when there's a technology that is broadly enabling it works in many different you know sort of across different kinds of systems and there are commercial opportunities the purpose of patents of course is to provide protection for companies and investors that might want to put money into technology or an application of that technology knowing that and be able to trust that they'll reprieve from that in the future because they've got some protection around an invention and it's a challenge when you have this kind of a you know broadly enabling technology right now there's a so there's been an ongoing patent dispute between two academic organizations primarily between MIT and the Broad Institute on the one hand and the University of California on the other hand and today you know the status of that is that you know lawyers are making a lot of money that will probably continue in the foreseeable future what I think is really important to point out though is that that patent situation has not held back the science so the science continues to advance very very quickly and one of the reasons for that is that any of us that are working in academic labs are not you know we're not held back by patents we can do the science that we want to do without worrying about who you know licensing taking a license to intellectual property and and it frankly also not has not held back investors and companies there are now three companies that are publicly traded soon to be more that are focused on CRISPR applications and many many many privately held startups that are using CRISPR why is that well because I think everybody figure that by the time you know there are actual products and applications that come online either the patent situation will have been sorted out or will have run out of years of protection anyway so whichever comes first so you know anyway as a scientist I feel grateful that we're able to continue to advance the work despite this ongoing patent dispute [Applause] [Music] you

Channel: University of California Television (UCTV)

Views: 30,454

Rating: 4.8955007 out of 5

Keywords: crispr, Jennifer Doudna, CRISPR-Cas9, RNA, biology, gene editing

Id: cUe-cOgpDDw

Length: 57min 37sec (3457 seconds)

Published: Sat Oct 26 2019