“The Magic of RNA: From CRISPR to Coronavirus Vaccines." presented by Tom Cech

good evening everyone and thank you for joining us tonight for the magic of rna from crispr to coronavirus vaccines we're excited to be joined by nobel laureate and distinguished professor tom check this evening we're going to allow another few minutes for attendees to join us and we'll be getting started momentarily some quick housekeeping items before we get started all attendee lines will be muted throughout the presentation attendees may submit questions by clicking on the question and answer or q a button located at the bottom of the zoom window we may not have time to get to your question but we'll certainly do our best to address the themes and ideas that are most common and as a reminder today's presentation will be recorded this recording will be added to the cu boulder retired faculty association's website and now please welcome dave casoy from the retired faculty association good evening everyone i'm delighted to have an opportunity to uh welcome you to the third of our distinguished faculty uh faculty series lectures uh organized by the boulder campus of the retired faculty association with the help of the office of faculty affairs and support from our colleagues in the strategic relations and communications operation today's event is an example of how the association brings a community together to witness and take part in all that cu boulder has to offer and more specifically with our distinguished faculty series we hope to showcase some of our finest professors and their extraordinary research and scholarly work i'd now like to introduce provost russell moore to get us started this evening russ thank you david and my thanks to the boulder faculty retired uh faculty association for their sponsorship of this of this distinguished faculty series and this particular event with tom my thanks to to my colleagues and faculty affairs and strategic strategic relations and communications for your hard work on this event as well i want to invite folks to watch for future events sponsored by the boulder campus retired faculty association which is doing a great job of advancing the work of some of cu boulder's leading faculty and of course when i say leading faculty there's no one more readily who more readily comes to mind than professor tom check tom joined the faculty here at cu boulder in 1978 became a howard hughes medical institute investigator in 1988 and then a distinguished professor of chemistry and biochemistry in 1990 in 1982 dr czech and his research group announced that an rna molecule from tetrahymena a single cell pond organism cut and rejoin chemical bonds in the complete absence of proteins creating an understanding that rna was not restricted to being a passive carrier of genetic information but could have an active role in cellular metabolism this discovery of self-splicing rna provided the first exception to the long-held belief that biological reactions are always catalyzed by proteins in addition it has been heralded as providing a new plausible scenario for the origin of life because rna can be both an information carrying molecule and a catalyst perhaps the first self-producing system consisted of rna alone in january 2000 dr czech moved to maryland as president of the howard hughes medical institute which is the nation's largest private biomedical research organization in a day in addition hhmi has an 80 million dollar a year grants program that supports science education at all levels k through 12 through medical schools and in international research in april of 2009 dr check returned to full-time research and teaching at the university of colorado boulder where he until recently was the director of the bio frontiers institute dr czech's work has been recognized by many national and international awards and prizes including the heineken prize of the royal netherlands academy of sciences in 1988 the albert lasker basic medical research award in 1988 the nobel prize in chemistry in 1989 which made him cu boulder's first of five nobel laureates and he also won the national medal medal of science in 1995. in 1987 dr czech was elected to the u.s national academy of sciences and also awarded a lifetime professorship by the american cancer society beyond his achievements and awards tom embodies all the best things about the life of science and the way we approach science at cu boulder he is devoted to interdisciplinary work dedicating to dedicated to teaching undergraduates focused on mentoring graduate students and post-docs including last year's nobel prize winner in chemistry jennifer dudena and centered in a life of inquiry collaboration and discovery he does all of this with the generosity of spirit and work that is remarkable he is in my mind not just a great scientist but a great person who happens to be a scientist it's my honor and pleasure to introduce our presenter this evening professor tom check thank you russ for that very generous introduction you've been a good colleague and a good friend since i've come back from maryland back to boulder 12 years ago so i'm gonna share my screen here and can someone confirm that that is visible yes okay good um so tonight i i've decided to share so first of all thank you for joining us and um tonight i've decided to share some information about rna that is mostly not our own work but that i thought would be of more general interest to the public and this is the crispr genome meditating and messenger rna vaccines these are two of the most spectacular scientific achievements since putting a man on the moon and i think that the public deserves to share in this excitement because after all it's your tax dollars that funded the rna research that paved the way for these great technical achievements now uh before i start the talk i just need to say that this is a picture of the carruthers biotechnology building on the east campus of cu boulder where we are privileged to to work and i i'm also required to disclose my relationships with um merkin company where i'm on the board of directors and storm therapeutics and icon therapeutics where i'm on the scientific advisory boards so i think before we talk about these rna technologies we should ask what is rna well you all know about dna the famous double helix and dna deoxyribonucleic acid you can tell by the name must be quite similar to ribonucleic acid now the dna double helix when it's copied into rna only one strand is copied so the rna is always single okay so this is a something i pulled off the internet to try to amuse people but since there's no left track on this talk i can't tell if anyone is chuckling or not um the information content of the rna is just the same as the dna so the the order of a's c's g's and t's along the dna is precisely copied into the rna now the rna can either be can code for a protein in which case it's called a messenger rna because it serves as a message between the dna and the protein synthetic machinery or the rna can be a non-coding rna that performs some other function within cells and this is the first example of the crispr genome editing and actually the rna has a non-coding role now this topic is of particular interest to many people in boulder because of the very recent award of the nobel prize in chemistry to jennifer doudna who trained in my laboratory at cu boulder in the 1990s and her colleague emmanuel sharpentier and so there was a lot of celebration when her discovery of crispr genome editing was uh recognized at this level now what does crispr do well it cleaves double-stranded dna but it's not as simple as the red scissors okay and this is where the rna comes in because the crispr machinery carries around with it this non-coding guide rna and that searches in the dna sequence for a match and when it finds a sequence that is complementary to that of the rna that means that g pairs with c and c pairs with g between the rna and the dna for example then it locks down and the protein component of the crispr machinery called cas9 cuts both strands of the dna so that now you have out of the entire human genome one place that has been cut well why is that of any interest or any use well because at this point cut dna is something that biological organisms have learned is a deadly event and so they have developed repair machineries that stitch it back together there are two basic kinds of these and i'm sorry that they have such technical names but this first one called uh non-homologous end joining just means that the two broken ends are glued back together during that uh gluing back together it's a little sloppy and so very often a small insertion or deletion called an indel shown in the bottom here in red is introduced at the repair point and that can be a itself a mutagenic event can inactivate a gene now the other possibility is that if there is a sequence um existing in the cell or if the experimenter provides a sequence called a donor strand of dna that has matches to the flanking sequences next to the crispr cut of the dna now you can use this uh homology directed repair to introduce purple sequences of your choice uh into the uh human genome and so you can imagine if the original human gene let's call it a a gene in a blood cell that is producing the hemoglobin the oxygen carrying protein if this individual had sickle cell anemia and had a mutation at a particular site the crispr machinery could put in purple sequences which would be the correct functional the ones we want sequences at that position and the sickle cell anemia would be alleviated so what are some of these medical applications that many companies are now engaged in non-stop research and development to try to make use of this crispr genome editing well where might the first successes be i think in addition to the sickle cell anemia that i mentioned other genetic diseases that are extremely deadly such as muscular dystrophy progeria these are really prime targets already for crispr genome meditating and also we can imagine that certain terminal diseases like cancer would be excellent candidates then what are some of the big technical challenges standing in the way of the implementation of crispr genome editing well you've got to get this combination of the cas9 protein and this guide rna molecule this non-coding rna into the relevant cells that's pretty easy for us to do in my laboratory with cells growing on petri dishes where you have really good access to the surface of the cell it's much more challenging to do in uh an entire human organism in the middle of the brain you know how would you actually get it to the relevant neurons and then we also have the technical challenge of specificity i have described the crispr genome editing as being entirely specific but in reality nothing is really perfectly specific there is always some low level of off target editing and one has to try to minimize that and also be aware that that off target editing could have unforeseen side effects finally we must be concerned about the ethical implications of changing the human genome these are perhaps not very great if we're changing a gene in a blood cell or in a liver cell because that wouldn't be passed on to the next generation it would die off when the person finishes their life span but germline editing which would be inherited is a whole nother matter and there is great concern in the scientific community and in the general public that this germline editing could be used to make designer babies not just determining uh the eye color or the hair color of your child but perhaps their height and weight uh a group of superhuman beings that is something we see in science fiction movies now with crisper genome editing it is probably technically possible and certainly something that we're not ready to embrace at this time now much has been written about these medical applications of crispr but i want to talk about something that's already extremely useful extremely valuable and that's the research applications of this technology because for the first time we can with surgical precision edit particular sites of the human genome and we're doing this have been doing this for half a dozen years in my own laboratory even undergraduates have mastered this technology it is that straightforward and robust of course the undergraduates are really good too now uh three sorts of research applications we can use crispr to inactivate a gene to help understand its function we can edit a single base pair in a gene to test uh what effect a mutation would have or to erase a mutation and see what kind of a good effect that might have and finally we can add sequences including encoding a fluorescent tag a little molecular light bulb to follow a protein as it moves around and explores a living human cell and since this third application is so visually uh exciting i thought i would focus on that tonight now the particular system that we're going to put the light bulb on is called telomerase some of you have heard of this as the immortality enzyme this is a little molecular machine that extends the ends of our chromosomes and it consists of an rna strand which was discovered by liz blackburn and carol greiter who won the nobel prize for discovering telomerase itself and then the rna strand also needs a protein to work along with it and this is called telomerase reverse transcriptase or tert for short and that was discovered by joachim lingner a swiss postdoctoral fellow in my lab here at boulder and just like the crispr machinery the telomerase machinery doesn't work unless it's got both the rna and the protein component one of the things that the rna does is it determines the sequence that's laid down at the end of the dna again by the principle of complementary base pairing a pairing with t c pairing with g now uh if you want to understand how this telomerase finds the ends of our chromosomes uh you well i'm sorry i forgot what the next slide was excuse me i wanted just to mention briefly that this telomerase is very um uh has a lot of medical interest also because if you have too little of it in your stem cells then they age prematurely and this contributes to another a variety of human diseases but if you have too much of it then this is sort of one foot in the door for cancer because this is the immortality enzyme and tumors are immortal and so uh most human tumors reactivate the otherwise quiescent telomerase gene actually the terp gene in 90 of human cancers and the way that it's reactivated or or the most common way was discovered by my friend levi garraway when he was at harvard medical school and he discovered a mutation in the regulatory sequence of the tert gene that telomerase reverse transcriptase gene uh in 2013 that when mutated attracts some regulatory proteins that pumps up the action of this gene and it is found in so many cancers that it is now the third most common mutation in all of cancer so back to this idea of tracking the telomerase around the cell we jan schmidt a postdoctoral fellow in the laboratory and artzog my long time research associate decided to do this live cell imaging using crispr genome editing the one component that needed to be edited was a protein called the sheltering protein that binds to the end of the chromosome that allowed us to mark the chromosome ends and then we also had to mark the telomerase protein with a different color and using crispr genome editing we could insert the sequences encoding these fluorescent tags right in the human genome so that everything was expressed in the normal way but when it was expressed it carried along with it this little light bulb and in the picture that in the movie that i'm going to show you here what you will see shown on the right is that most of the telomerase is exploring the human cell nucleus by rapid diffusion each chromosome end called a telomere is probed thousands of times per dna synthetic phase of the cell cycle and then occasionally the telomerase sits down on a chromosome end for long enough to actually extend it and you will be i think amazed as i was to see how much motion there is within these live cells this is not sped up this is real time movie 12 seconds in the life of a cancer cell and you see the green dots which are the telomerases are moving around rapidly and the red dots which are the chromosome ends look like they're static they move very slowly over a long period of time but they are in this 13-second movie essentially stationary and now i'm going to play this once more and focus on this little yellow dot this is where a telomerase has found a chromosome in so the green is overlapping with the red making for yellow and you can see that they are holding on to each other for the entire length of this movie and we think that that is the event that actually is important for extension of the chromosomants now when you're doing this kind of research you can't just look at the pretty pictures you have to use tracking software to track the trajectories of thousands of these telomerase particles through the nucleus here you can see that they are really exploring most of the nucleus sorry for the technical term here but there's one area called the nucleolus that is actually not being explored there are no chromosome ends in the nucleolus so it doesn't waste its time looking in there and then by analyzing these data we come up with a model for the dynamics of how human telomerase finds this needle in a haystack spot this very end of the chromosome which is such a small fraction of the chromosome length so it probes the uh telomere many times uh during the during a cell cycle but if it doesn't find the very end of the chromosome it gets released again and then much more rarely through both protein protein interactions with the telomere protein and this base pairing interaction between the telomerase rna and the dna at the end of the chromosome which i showed in that earlier painting now it's locked down long enough to actually do the extension and using this technology we can even examine the effects of various cancer drugs that have been developed against telomerase such as this jiron drug which binds to the rna subunit and we can see how that interferes with the recruitment of the telomerase to the chromosome end so that's one example then of crispr genome editing as a research tool and every day there are a hundred different applications that are published in the scientific literature it's literally being used by tens of thousands of laboratories around the world so let's move on to the second topic which is something that you see every day on the news and on your computer that vaccines against the coronavirus are obviously something that is really uh front and center right now so what is a vaccine it is um something that primes our immune system it sort of says heads up something dangerous is coming right you need to get rid of it and so in order to prime the immune system to recognize the coronavirus you don't need to use the whole virus although you could that was a traditional vaccine strategy but all you really need is this so-called spike protein which is uh painted by the artist sort of colored red in this particular rendition it's not really red and that is the part of the coronavirus that is first seen by our immune system so if we can prime the immune system with just that protein that is enough to get to vaccinate one against the virus and the nice thing about using just the spike protein is that without the uh rna heart of this virus which is the infectious part the spike protein is completely uh benign okay it's not infectious by itself so that's a good thing so um what does your immune system do when it sees uh the spike protein well it activates two kinds of of activities within the immune system the b cells which are bone marrow cells make antibodies which can bind to that spike protein and thereby prevent the um sort of cover up the spike protein prevent it from entering human cells or the immune system can activate t cells thymus cells that give a cellular response to attack and kill infected cells which is also a good thing not for that particular cell but a good thing for the survival of the whole organism namely us now before i go on with the mrna let me just remind you if you don't haven't seen this before that vaccines are generally the safest of all of the approved drugs that you've heard of well why do they require so much scrutiny why are the safety standards for vaccines so much higher than for other drugs because they're being given to large numbers of healthy people so if you have um a one percent chance of getting a serious illness from the vaccine that's completely intolerable if you're going to be giving it to a million people and we're gonna eventually give it to children and so that's why these vaccines have to be tested especially thoroughly before the fda will approve them and then that's not enough they are monitored for many years for their entire lifetime after they are marketed and so if you look on the cdc website you can see uh fantastic data that's been collected for example from the last 50 million kids who've received the chickenpox vaccines there's been less than one serious event per million vaccinations and by the way that number of serious events is much lower than what you would get if you had a million kids with the chickenpox that would have a much higher level of serious events so i urge you if you have some neighbors who are hesitant about vaccines to take a look at this cdc website now what are the ingredients that you need to mix together not to make cake but to make a coronavirus vaccine well there's several different recipes that can be used and though once some of these use like the johnson johnson vaccine recombinant adenovirus a cold virus encapsulating a dna some of the chinese viruses are weakened forms of the of the coronavirus itself but i'm going to talk about these two at the top because i am dr rna and i love rna and i'm so excited that the first vaccines to be approved were the messenger rna vaccines wrapped up in a greasy little ball called a lipid nanoparticle now remember the first story the crispr story was the non-coding rna now we've got the messenger rna which is the coding rna and what do you suppose that messenger rna needs to code for it needs to code for the spike protein so the way we normally read about information transferring biology in a high school textbook or a college textbook is that the gene there's a gene for every protein the spike protein would have its specific gene double helical dna that is made into messenger rna which then orchestrates the production of that particular protein but what scientists at moderna and at biontech pfizer realized was that you could short circuit this pathway all you needed was the messenger rna because it could make the protein you don't need to mess with the dna at all and given that there were zero examples of mrna vaccines ever having been successfully developed and approved what would be the chances that the first one would be successful i don't know but i think there was some luck involved that we really lucked out that the first one was successful because this doesn't usually happen when you step up to the plate for the first time and hit a home run at the first ball that is pitched and the reason that i'm excited to share this story with you is because it's your dollars your taxpayer dollars that funded the fundamental research into how rna works independent of knowing about that there would even be a coronavirus or a pandemic independent of any applications that was the reason that these companies were able to do this so quickly and so successfully so some of the technologies are as follows rna sequencing which was done just a year ago was first revealed in january of 2020 revealed the sequence of the spike protein that was the target for the mrna vaccine virology uh was critical because it enabled us to understand how the spike why the spike protein was the thing we needed to to cap off to prevent the virus from entering cells nucleic acid chemistry was critical to make the rna stable and safe rna biochemistry how to make a ton of rna in vitro that's a latin term it means in glass and now we use plastic test tubes but we still call it in vitro for old time's sake and these lipid nanoparticles that package the rna so that it could get into cells so all of this was worked out by fundamental scientists who didn't know what the application would be but were just following their curiosity and knowing that rna was going to be really important now there turns out to be a enormous contribution from cu boulder to these technologies so professor marvin cruthers in biochemistry invented chemical synthesis of small fragments of dna the technical term for these are oligonucleotides and these are absolutely essential tools for sequencing the code of the coronavirus spike protein so he did this he developed this in the 1980s and it has applications to absolutely every biomedical problem including of course sequencing the coronavirus professor ulenbach uh also in the biochemistry department in the 1980s chemistry and biochemistry developed uh and really modified and tuned and and and really got this in vitro transcription of rna turned into a robust technology and this turned out to be the same method that moderna and biontech visor used to synthesize the mrna and are using right now to synthesize the mrna for their vaccine and again you know back had no idea that this was going to be uh important for fighting a pandemic he just wanted to make specific rnas for research purposes which many of our laboratories do all the time now the other thing that the that these pharmaceutical companies should be credited for is the way that they sort of overlapped the development of these vaccines normally these different blue bars the clinical trials the manufacturing the fda approval would all be done you'd finish bar blue bar number one and then you'd start blue bar number two right and then you'd start number three so the blue bars would be lined up in a straight row but by overlapping them this they were able to achieve a an approved vaccine in one year instead of the typical five to eight years that it would take so it was a record not just by a small amount but by a huge factor now remember we don't have problems we only have challenges and there are some challenges with these mrna vaccines they are not perfect tools for fighting the virus first of all because mrna vaccines are a new modality manufacturing and supplying them has been more challenging than it would have been with a traditional vaccine a cold chain is required which means you have to keep the vaccine depending on the which one it is either frozen or at least very cold the whole time it's being shipped and stored this is particularly a problem for distributing it to rural areas the durability of the vaccine is means how long after you're vaccinated are you still protected well we'd all like to know the answer right now because we fast-tracked it all we know is that it's good for six months could it be good for 10 years possibly could it be good for a year at a time so that you would need a booster shot like an annual flu vaccine that's possible but we don't know yet and we will know within another year how durable this response is you've heard a lot about the variant viruses the mutant viruses that are being spun off all the time by the coronavirus and some of them are partially resistant none of them so far has been completely resistant to the vaccine but some of them like the south african variant are partially resistant and that's not good news but with an mrna vaccine any undergraduate in my laboratory if they were given the sequence of the new variant could design a vaccine against it in a week so that's another exciting component of this mrna vaccine technology that it's tunable to however the virus changes you can tune the vaccine and then another challenge is a lot of anti-back sentiment people who think that they don't need the vaccine and don't realize that their reluctance to get it is actually having a big effect on their friends and relatives and the whole community and that anti-back sentiment is strong even in the boulder valley and so uh nonetheless despite those challenges i think it's great to have a light at the end of the tunnel and i would like to thank both the people within my own research group and the people who i talked about for the mrna vaccines of akionbek marv carruthers the dedicated scientists at moderna and biontech pfizer and for j and j as well um i mean i love mrna vaccines but i think that one should get any vaccine one is offered and we also thank the howard hughes medical institute and the national institutes of health for funding and the damon runyon cancer foundation funded ian schmidt when he was here he's now on the faculty of michigan state university and i thank you for your attention and now i would like to introduce um my post-doctoral fellow lynnea janssen or lynnea jansen fritzberg if she could reveal herself at this time i first met linnea when i was giving a research seminar at the university of california at santa cruz which is a a wonderful center for rna research much as boulder is and i was able to get her interested in applying to come to my laboratory for uh her postdoctoral work and um you probably can't tell that she's actually in the area because she could be um zooming in from anywhere but she in fact does work in the lab and she will tell you a bit about that before she fields uh the questions lynnea thank you tom for the introduction um and good evening everyone as tom mentioned my name is mania and i'm a postdoctoral researcher in tom's lab and i'm just going to quickly mention what i do in the lab so i study how rna regulates epigenetics and epigenetics refers to the dna sequence independent changes and how genes are expressed so all the cells in your body have the same genetic materials but epigenetic marks determine which cells are turned on or off to produce a specific cell type which is why a skin cell and a muscle cell for example even though they have the exact same dna look and behave very differently so specifically i look at how rna regulates the enzymes responsible for adding metal marks onto dna and dna methylation is an epigenetic mark that often serves as a signal for genes to turn off and this is important because abnormal dna methylation is one of the earliest signs of cancer so i'm currently looking at how rna regulates the activity of a protein called dna methyltransferase 1 or dnp1 for short and i'm interested in how these protein rna interactions vary between both healthy and cancerous cells so i will serve as your moderator for tonight's discussion we will start with a couple of questions that were submitted during registration and we will then move on to questions from the audience and if you have a question that you think of so tom if you want to pop back up on the screen i'm here so here we go um could could crispr be used to enhance or establish metabolic pathways in microbes so that a colony could efficiently consume greenhouse gases for example in smokestacks to produce more sustainable and useful byproducts besides biomass yes quite remarkably the crispr gene editing machinery is active in bacterial cells where it was originally isolated from but also in crop plants rice and corn also in the yeast that is used to make bread and beer also active in all mammalian cells in which it's been tested this is not something you could have necessarily predicted but it turned out again sometimes it's it's good to be lucky and so it can be used to re-engineer uh bacteria and of course then the other part of your question which would take a whole hour seminar to cover is what ex which genes exactly would you like to modulate or add to bacteria to allow them to uh have these positive effects on the environment i'm going to keep all my answers right thank you rather brief so we can get any of your questions as possible i think that is a good idea we have um 50 questions so far so i'm going to ask another of the pre the questions that are asking um the registration and then i'm going to move into the questions the q and a's that have been asked right now because some of them are overlapping with the early ones so we have a person asking does the fast track production of the chronovirus vaccine create a bad precedent for the development of future vaccines well does the fast track create a bad precedent um certainly uh there there was during the approval of it a sort of a trade-off between um uh between being really careful and methodical about the about the trials and the the international uh need really for a vaccine as people were were dying every day and so just as in most decisions in life there's there's you need to balance the two things um i'm not sure though that it's going to turn out to be a bad precedent i think that it may turn out to be a good precedent and reveal that some of the extra excess time that we've been taking to test some of these medicines has not actually been adding much value but has been slowing things down and now that the first mrna vaccines have been shown to be safe and effective i would imagine that when the next mrna vaccine comes along that scientists are going to say you know we do need to do some safety and efficacy studies but we have a track record of success maybe we can accelerate these processes all the time instead of just when there's a pandemic great um so now i'm going to move on to questions from that were submitted during your talk is um and i'm sure this has been uh something that a lot of um people in the general population have been curious about so anti-vaxxers are claiming that the clova 19 vaccine changes our dna please comment on this thank you well one of the one of the beauties of an rna vaccine is that the possibility of of dna getting into your chromosomes is gone because there's no dna being introduced in the vaccine the vaccines that have dna in them like the j and j vaccine that there there is dna in those vaccines the the j and j and the astrazeneca and so there is a hypothetical possibility that that dna could find its way into the human genome and i guess what it would be likely to do if it did that would be to produce some of this spike protein which would then hopefully give one continued protection but it wouldn't be something i would want to see happening and that's why so much safety study had to be done before approval of those vaccines so we do not see that event occurring with the dna vaccines and i would argue that it's just not even a possibility with the mrna vaccines thank you um so here's a question that is similar to a question that was asked during registration so i'm going to attempt to combine the two um so a viewer has a question my wife has asthma and is easily allergic to things is the vaccine unsafe for her and are there any precautions she should take and i'm going to combine this with a person that also asked a similar question about autoimmune disorders and if there are specific precautions people with autoimmune disorders should take it's an important question and when i'm giving a talk to a thousand people i'm certainly not going to give medical advice and so and also i am not qualified to give medical advice so please talk to your physician about this um i think an answer that you are likely to get from your physician is that if you've had uh if you've tolerated other vaccinations pretty well there's no reason to think you won't tolerate the coronavirus vaccine equally well if you've had severe reactions to previous vaccinations then that would be a reason for special caution great so a general question here just about rna we haven't asked or somebody is asking what decides if rna is coding versus non-coding yes um first of all the the coding rnas have to get exported from the cell nucleus to the cytoplasm where they're read out into a protein sequence and so special signals on the rna that allow it to get exported from the nucleus to the cytoplasm is one answer the other thing is that there are little codes in the rna sequence itself that determine whether it's going to be coding and the first of this is the triplet a u g which means start making a protein right here okay and so all of the mrnas would have that aug or occasionally a related sequence followed by codons for the individual amino acids right lysine tryptophan uh phenylalanine etc going down the chain and the non-coding rnas uh don't have that code embedded in the sequence of the rna good question what are your thoughts on using crispr to break down tumors well i i think that um so so crispr can be used to inactivate genes and it can be used to add information and there are genes called oncogenes which enable a tumor to divide rapidly and so crispr inactivation of those oncogenes perhaps even the tert that i talked about would be a good target that's that's uh just just um which i say uh logically that is that's a that would work right that the the logic is fine how easy that would be to implement and how successful it would be requires a lot of development and a lot of clinical trials and on the other hand there are tumor suppressor genes that help us survive tumors that are often inactivated in cancer and in those cases reactivating the tumor suppressor gene would be something that crispr in principle could could also achieve so i think lots of potential and much research needs to be done before we know how practical such approaches are great so another coveted question so why are health experts saying that even those who already have had covet should get vaccinated why would the vaccines be more efficient or more effective at giving people long-term immunity when the actual actual viral particles themselves may not yes so um the the very perplexing and unusual thing about this particular virus is the range of severity of infection so many people probably 90 percent of people certainly most of the young people who get infected have a very mild infection and they don't produce a lot of antibodies so what's been found is that the vaccine produces 10 times more uh antibodies against the coronavirus than than one of these mild infections does and so um i that's the reason that they are recommending vaccination for people who have already had the disease i i suppose if you had a extremely severe case a near-death experience with a real high viral load then you might be okay but that's a very small percentage of the infected people who'd be in that category great um are the mutant viruses showing variants only on the spike protein for which the current vaccines target no rna viruses are sloppy replicators they make mistakes all the time when they copy their rna genome and they make mistakes throughout the 30 000 subunits called nucleotides of the rna chain it's just that most of those changes are uh not um it's displayed on the exterior of the virus only and only the ones on the spike protein and the spike protein is what the virus needs to get into the cell through something called an ace receptor and so that's why all of the focus is on the mutations within the spike protein great uh will mrna be the new standard for creating new vaccines i think there's a i think this is really revolutionary right and so should can we see a much better flu vaccine better tuned to you know uh the flu that is originating in asia and and coming in our direction in the future based on mrna uh i think that that this has opened a door and uh the possibilities you know maybe even a cancer vaccine of some of some sort might come out of this so i'm hopeful um but it's too early to declare victory and we need more students and research fellows like linnea and others working on rna before we can um really explore all of these myriad of possibilities that have now been opened up for us and so this is a bit of a bureaucratic question but we have somebody asking since these vaccines are currently emergency use authorization only do you have any thoughts on the time frame for when the fda will actually approve them um that's a good good question i have not read up on that particular question i would imagine that they might want to see a year or two of track record for safety and efficacy before they would give it regular approval rather than this emergency use authorization but i don't have that's just a hunch i i don't know an exact number and here we have a few uh people asking a similar question so there's a comparison so we have people since you talked about both crispr and the mrna vaccine people are asking if crispr was used at all in the development of the mrna vaccine or is there any link between the two um there there is no direct link uh except that they both had this cu boulder connection which i pointed out and they are both involved my favorite molecule ribonucleic acid i agree how long of a dna sequence can be inserted by the cas9 protein um yes well the the they can be quite long but but uh the efficiency can be quite low if you try to insert a very long sequence so you might have to try multiple times before you get success which is fine for research purposes but a problem for medical applications let me just say that this protein light bulb that we inserted to make the tert protein fluorescent is not a very small molecule it has um um i can't remember exactly let's say it has a thousand amino acids in it and each amino acid requires three rna nucleotides to code for it so that would be 3 000 nucleotides that would have to be inserted into the dna and so we were able to insert 3 000 so it doesn't have to be a small change like for sickle cell anemia where you'd want to change just three of these units you can change thousands great so this is an interesting question so how does one reverse engineer mrna from knowledge of protein like the spike protein yes this was figured out in the 1960s in a heroic effort by um marshall nurenberg who was at the nih and gobind karana who was at the university of wisconsin and then at mit and they won the nobel prize for deciphering the genetic code and so once you have this table of codons like aug means methionine uu means phenylalanine this table which was figured out in the 1960s and is in all of our textbooks and you can find it on the internet now once you have that you can go from mrna sequence to predicting very accurately what the protein sequence is or you can go from protein sequence and figure out how you would make an mrna to code for that protein and that's the kind of thing that in our classes in our when we teach biochemistry or molecular biology that'll be a test question right on the test we'll say if you want to make this protein what kind of rna do you want to make what sequence and the students figure it out great so it's eight so i'm going to ask two more questions before we go to closing remarks so this has been this question asked something that has been a topic of discussion um in the scientific community for a while but with the rise of the popularity of crispr what measures are in place ensuring that the creation of designer babies is prevented well first of all the scientists have gotten together and and themselves put a prohibition on germline editing now of course that doesn't just because a group of influential scientists decides that this is something that shouldn't be allowed doesn't prevent a rogue scientist and there was one in china who went ahead and made designer babies a couple of years ago he was put in jail in china for for having done this but um it does it just like any other technology good people can make the right decisions and the right prohibitions and it doesn't really give you an iron-clad guarantee that in some rogue country or with some rogue group of scientists that someone might try to break through those ethical barriers but we're doing the best that we can great and so to end on a hopeful note here i'm going to ask this question um are there other deceases you feel might be a good target for future mrna vaccines for future mrna vaccines well yes i think that um particularly anything that changes rapidly um through by mutation um that this will end up being a a very good approach because the vaccine can be changed so rapidly to match the mutated virus and so many rna viruses including the common cold and flu virus might be finally um uh better attacked with with vaccines through through this technology i think that the more um uh pie in the sky but exciting possibility would be some kind of a cancer vaccine using the information of oncogenes the sequence of the oncogenes and the fact that they are expressed by by by in tumor cells as a possible lead but that's more speculative great thank you and thank you everyone for listening and now we're going to have some closing remarks from dave kasoy i'm very pleased to have an opportunity to thank uh professor tom czech uh dr lynnea uh jansen fritzberg and all of the people who joined us tonight to get a little bit of an education about all of the things that the the these experts have been talking about we're really pleased to offer these kinds of seminars in the future we'll have another one on april 21st we're in the uh in the fourth of our distinguished faculty series and we're delighted to be able to offer that to a very wide public stay tuned thanks very much good night [Music] no i was trying to figure out how to do two things at one time you

Channel: University of Colorado Boulder

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Length: 66min 18sec (3978 seconds)

Published: Wed Mar 17 2021