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George Church, Ph.D. is a professor of genetics at Harvard Medical School and of health sciences and technology at both Harvard and the Massachusetts Institute of Technology. Dr. Church played an instrumental role in the Human Genome Project and is widely recognized as one of the premier scientists in the fields of gene editing technology and synthetic biology.
In this episode, Dr. Church and I discuss:
"I think we didn't realize that we were on an exponential when we started sequencing." - George Church, Ph.D. Click To Tweet
On February 28, 1953, scientists James Watson and Francis Crick made a remarkable announcement. Building on nearly a century of groundwork laid by a handful of other scientists, Watson and Crick proposed that DNA, the fundamental genetic material of nearly all living organisms, was arranged in a double-helix, a ladder-like structure that twisted on itself into its now well-known corkscrew shape. Research on DNA grew by leaps and bounds in the years that followed, but an understanding of the role the twisted molecule played in health and disease was hindered by an incomplete picture of its sequence.
Efforts to unravel that sequence came to fruition some 50 years later, when scientists made an even more remarkable announcement: They had sequenced the human genome – the entire set of genetic instructions found in a cell. This monumental task was made possible by the Human Genome Project, a multinational effort involving government agencies, research institutes, corporations, and countless scientists. Their draft covered 99 percent of the euchromatic genome (the part enriched with genes) and was estimated to be 99.99 percent accurate.
The Project was no small undertaking, lasting 13 years and costing nearly $3 billion. Since then, advances in sequencing technology have made genome sequencing exponentially faster and widely available – at a fraction of the cost. With the genome sequenced, scientists are now embarking on even more ambitious projects, focused on understanding and preventing many chronic diseases and ushering in a new era in which synthetic biology – redesigning organisms and engineering them to have new capabilities – offers the promise of a healthier future for not only humans, but other species, too, with applications in the worlds of ecology, conservation, agriculture, and likely others.
The knowledge gained from the Project has given rise to many new therapies, including the now-famous CRISPR-Cas9, "CRISPR" for short, a powerful gene-editing technology that allows scientists to tweak a single disease-causing gene, essentially nipping the disease in the bud. But CRISPR, which Dr. Church sometimes refers to as a "hatchet" or "genome vandalism," has its flaws. It is notably imprecise and limited in its scope. He and others in the gene-editing world are now employing multiplexed gene-editing technologies, targeting not just one, but multiple, specific DNA regions in a genome with high precision.
Having achieved the initial sequencing aim of the Human Genome Project, sometimes retroactively designated Genome Project-Read, a new project has come to the fore: Genome Project-Write, which aims to reduce the costs of writing and testing large genomes and synthesizing entire genomes, starting with the Y chromosome, which contains the fewest genes – from scratch.
Sometimes termed CRISPR2.0, a recent and exciting advance in gene editing technology called base editing has enhanced the precision – without introducing double-strand breaks. In one iteration, one of Cas9's cutting enzymes, a nuclease, is deactivated, and another enzyme, a deaminase, is introduced. This new CRISPR complex, known as a "base editor," can modify a single DNA nucleotide without introducing toxic double-strand breaks. This technology has greatly expanded the multiplicity of edits that can be introduced into a given cell, a type of genomic editing known as multiplexed editing. Their efficiency, specificity, and low genome damage make base editors ideal tools for multiplexed genome editing. While this is a remarkable advance, Dr. Church proclaims that many other powerful tools are on the horizon.
An example of base editing has now reached human clinical trials involving the PCSK9 gene and familial hypercholesterolemia.
The number of per cell edits continues to increase: from 62 edits in its first iteration to deactivate porcine retroviruses, which prevent pig organs from being transplantable to recently, 26,000 edits. This was accomplished through the use of new base editors that don't impose the cytotoxic double-strand DNA breaks made when genomic engineers instead use the original CRISPR, which relies on the native Cas9 enzyme.
As each new milestone in editing is surpassed, entirely new paradigms of what may be possible with genome engineering emerge. One example of mind-boggling applications that Dr. Church and his colleagues hope to develop: producing human cells with perfect viral resistance.
Viruses have played extraordinary roles in human evolution, shaping and influencing our modern bodies. But viruses and the diseases they cause have exacted an immense toll along the way, leaving in their wake a swath of misery, suffering, and death. Smallpox, the deadly disease caused by the variola virus, ravaged humans for thousands of years, claiming the lives of as many as 500 million people in the last century alone. The disease was eradicated, however, in 1980, after a global effort of vaccination, testing, and containment. Many deadly viruses remain, including Ebola virus and human immunodeficiency virus, and new viruses will likely emerge in the future.
But what if we could eradicate all viral diseases by making cells resistant to the viruses that cause them? While this seems a radical and vast undertaking, Dr. Church thinks it may be possible within the next decade, starting with industrial microorganisms, such as those used in large-scale manufacturing processes, and genetically engineered cells, such as those used for immunotherapies. His laboratory has already made progress on this feat with the bacterium Escherichia coli, the first of what might be a host of genomically recoded organisms and perhaps setting the stage for preventing many other diseases, including cancer.
Making cells resistant to viruses exploits a fundamental aspect of how the instructions in DNA are converted into a functional product. Each strand of DNA is composed of four nucleotide bases, identified by their initials, A, C, G, and T, and strung together by chemical bonds. Translating the strand into a protein is famously made possible by a process that involves specific combinations of three adjacent nucleotides called codons. Codons are interpreted by the ribosomal and translational machinery of cells as the genetic instructions for making specific amino acids, which form the basis of proteins.
Translation of these triplet codons to the corresponding amino acids is universal across the tree of life, from single-celled organisms to mammals, and comes packed with redundancy. Sixty-four possible codons code for only 20 amino acids and a single stop signal. Consequently, some amino acids can be made from multiple codons. For example, serine and leucine correspond to six different codons each, making them particularly interesting for genetic manipulation.
Codon degeneracy, the term for when several codons translate to the same amino acid, arises because there are more codons than encodable amino acids. Exploiting this phenomenon allows scientists to build a firewall against viral gene transfer – an essential aspect of viral replication.
Borrowing from a concept of computer programming, reorganizing code without changing its underlying function is sometimes termed "refactoring." Herein, we might find an elegant analogy!
What if DNA itself could be refactored? If such a thing were possible, one result might be what is now known as a genomically recoded organism, something that could only exist in an era of multiplexed editing.
Dr. Church's lab has explored many concepts not too far removed from such scenarios:
"All viruses, as far as we know, depend on the host genetic code, the translation ribosomal machinery. If you can change that code enough without hurting the host, the virus can't mutate." - George Church, Ph.D. Click To Tweet
Theoretically, if a host's genome could be precisely recoded with fewer or, better still, swapped codons, it might happily continue chugging along making the same proteins. Viruses, on the other hand, will encounter an immense challenge: far from parsimonious, they have grown accustomed to utilizing the entire universal codon alphabet, including the redundant codons, to replicate themselves within cells. A virus in this setting will find itself in an unfavorable translational environment – and rendered impotent. Presumably, the host will be functionally intact because of the code's redundancy: it can still make all the proteins it needs, but it now has viral resistance. The magic of refactoring – improving the design of a legacy system while maintaining function and, in this case, imparting a generalized "firewall" – prevents viral infection.
With enough changes to the translation machinery and codons of a host cell, a virus likely cannot evolve to compensate. The gap between the expectations of its program, shaped by eons of evolution, may be simply too great to easily adapt to the new translational environment of the engineered cells, an opinion held by Dr. Church and other synthetic biologists.
As Dr. Church explains, this technique has immense implications due to its generalizability. While it requires vast and precise multiplexed editing capability or even rewriting the genome from scratch, it may work across the entire tree of life. That's because the technique changes not just the translational apparatus, but also all variations of the codons.
Applying the computer programming concept of refactoring to a biological system paved the way for the paradigm-shifting innovation of recoding. Cells could be programmed to behave and function as they ordinarily would but with profound differences in their underlying code and translation apparatus, making them immune to all viruses and even horizontal gene transfer – a boon to preventing the unintentional spread of lab-produced genetics to wild-type organisms.
Of course, viral diseases aren't the only afflictions from which humans suffer. Aging, and the diseases that accompany it, likely represents an evolved species-specific developmental program. It is one of the key drivers of disease and death and is characterized by a host of observable biological patterns, or hallmarks, of dysfunction.
Addressing these hallmarks, which include genomic instability, epigenetic alterations, and loss of proteostasis, among others, is essential to forestalling aging and restoring youthfulness. Dr. Church and his colleagues are addressing some of these hallmarks via delivery of genetic instructions for making growth factors in dogs. Our canine friends make excellent models for studying the effects of the growth factors because they share so many of the same environmental exposures as humans – and because we care so much about them.
The Human Genome Project and its legacy projects have opened the door to myriad possibilities in eradicating disease and promoting healthspan and longevity. In this episode, Dr. George Church and I discuss many of these possibilities, as well as the scientific and ethical challenges researchers face in pursuing these goals.
Biotech companies
The Human Genome Project
How new DNA sequencing techniques made it feasible to sequence all human genes.
The importance of the first human reference genome. 1
How the Human Genome Project aspired to sequence all human genes to more fully understand health and disease.
What the completion of the Human Genome Project revealed and why we need more reference genomes.
How new technologies rapidly developed, allowing for exponential progress.
The atomic precision of synthetic biology
How biotechnology is increasingly being harnessed as a powerful manufacturing tool.
How a biological system's unique ability to self replicate is vital for its use in manufacturing.
Genome Project-Write
How writing the human genome may help us better understand it.
Writing a human Y chromosome (from scratch).
What if you could eliminate viral disease?
How genetic recoding – profoundly changing a cell's genetic code such that a virus cannot infect and utilize its ribosomal translation machinery – renders the host resistant. In a recent experiment Dr. Church's lab accomplished this feat in the bacterium E. coli. 1
De-extinction and reinstating lost traits and genes
How de-extinction requires highly multiplexed editing or complete genome rewriting to reinstate lost physiological functions, for example cold resistance from the woolly mammoth.
The Vertebrate Genomes Project
How the Vertebrate Genomes Project – a massive endeavor to sequence the DNA of all known vertebrates – aims to generate reference genomes for 70,000 species. This effort may participate in saving keystone species, protecting genetic diversity, and preventing or reversing the process of extinction. 1,2
How freezing, documenting, and creating databases may not be enough to restore extinct species — if we allow them to go extinct by abandoning more practical conservation efforts.
AlphaFold and other AI tools
How Alphafold can accurately predict a protein's three-dimensional structure from its sequence.
How genetic material is analogous to computer software that can be read, written, programmed, and debugged.
How the eradication of smallpox became an example of the equitable distribution of technology since all future generations benefit.
The Genome Project-Write and the increasingly credible goal of being able to write large or entire genomes from scratch, starting with the novel synthesis of an entire human Y chromosome. 1
CRISPR vs. Base Editing (emerging tools of genetic engineering)
How CRISPR is an immense advancement in gene editing, but does not offset the need for other tools that allow scientists to read DNA and track editing progress. Moreover, editing techniques that pre-date CRISPR, such as homologous recombination, allow for precise and long-distance editing. 1
How most approved gene therapies involve adding a gene, typically without CRISPR. For rare diseases this is a very expensive process.
How genetic counseling can inform people whether they are carriers of genetic diseases allowing them to make preconception choices.
Why multiplex editing will change the world
How removing endogenous retroviruses from the pig genome may allow pig organs to make up the shortfall of human organs for transplant. 1
How visionary projects such as multi-virus resistance and ecosystem diversity will require multiplex genome editing. 1
Molecular flight recorder
Preventing viral spillover and enhancing livestock
How gene-editing could be used to eliminate zoonotic viruses that spill over from livestock.
How germline editing pigs against African swine fever virus is the first example of using CRISPR to eliminate a mammalian virus in the environment. 1
PCSK9 gene therapy for cholesterol
How the rare null variant of the PCSK9 gene is associated with low cholesterol and favorable cardiovascular outcomes. In an ongoing clinical trial participants with familial hypercholesterolemia are receiving a base-edited version of the PCSK9 gene. 1
Is aging an evolved program?
How addressing all the hallmarks of aging is paramount in achieving youthfulness at an advanced age. 1
How cells can be rejuvenated by cloning or adding Yamanaka factors
How factors in old blood can affect young animals and how this is demonstrated using parabiosis experiments.
Treating aging with a combination gene treatment
Why Dr. Church thinks that gene therapy for aging dogs and xenotransplantation projects may be ideal pipelines toward creating therapeutics that can unlock human potential.
How Dr. Church is working on a combination gene therapy to reverse age-related biomarkers, focusing on genes with cell non-autonomous effects, producing soluble factors that can rejuvenate the whole body – similar to how factors in young blood revitalized old organs in animal studies. 1
Does animal research help us understand human aging?
Human organoids as a model and therapeutic
How human organoids are becoming increasingly accurate, and this rapidly developing area may one day include therapeutics. In one experiment, a human brain organoid was modified from apoE4 to E3, and in another a human organoid rescued mice from demyelinating disease.
Could engineered transplant organs become better than the originals?
How genetic techniques may facilitate the use animal organs suitable for human transplant. Furthermore there is a possibility to engineer enhanced qualities, like cryopreservation and resistance to DNA damage.
Embryo editing controversy
Dr. Church shares his perspectives on complex issues such as germline gene editing, whether there is a responsible way to use it and how it differs from embryo selection, and equality of access to biotechnology.
How human germline editing using CRISPR sparked international outrage.
How the public has accepted in vitro fertilization, which in 1978 was quite futuristic.
Whether the public ought to understand gene editing or the risks of other germline mutagens, such as chemotherapy or high-altitude living.
Gene editing for space travel
Can synthetic biology alleviate poverty?
How Golden Rice is an example of a genetic technology that alleviates a disease of poverty. Rice engineered to contain provitamin A may prevent blindness in people who eat a rice-based diet, however, it is controversial and has been opposed by some groups. 1
Are in vitro fertilization and embryo selection similar to editing?
How next-generation embryo selection may be an intermediate step to evade some genetic diseases before germline editing
The occasional cost of brilliance and neurodivergence
Whether there are advantages of gene variants that may otherwise be thought of as deleterious.
Eradicating disease with Gene Drive
How a type of genetic engineering called Gene Drive may produce insects unable to carry human diseases like malaria or Lyme disease.
Technologies to solve Lyme disease
Whether a Lyme disease vaccine may be revisited now that Lyme and other tick-borne diseases are more serious and widespread.
Dr. Church's experience with narcolepsy as a bridge to creative insights
Why George encoded his book in DNA 1
Dr. Patrick: Hey, everyone. Today I'm extraordinarily excited to bring to you, Dr. George Church. It's really a special opportunity to talk to Dr. Church because he's one of those rare living historical figures, whose work is so vastly influential that it can change our perspective on the potential of an entire field. In my opinion, this gives his generally optimistic take on technology and the future a very special weighting. Through his work in the Human Genome Project, in particular, he has directly contributed to exponential shifts in understanding feasibility and capability in the field of biology.
The Human Genome Project began as a $3 billion moonshot shortly after Dr. Church first pioneered a method of direct DNA sequencing in 1984. The goal, to sequence a single reference genome for humans. Completing the initial aim of that project, Dr. Church and his collaborators and colleagues ultimately set us on a path to where we find ourselves today. Sequencing is now over 10 million fold cheaper, and most people can get their genome sequence inexpensively if they so desire.
But where do we go from there is the question. Arguably one of the most important geneticists of our time, Dr. Church helped initiate the Human Genome Project in 1984 and the Personal Genome Project in 2005. His lab was one of the first that showed CRISPR-Cas9 worked for precise gene editing in normal human cells. And he has been behind countless other scientific innovations and disruptions, specifically in the world of precision genome sequencing.
Dr. Church has described the key theme of his lab as technology development, radical transformative technologies. So, let's talk about those. George, it's hard to know where to start, large genome-writing history, universal donor cells, multiplex editing, and the ability to perform thousands of edits in a single cell, organoids. But maybe we can just start with the Human Genome Project. What is the back story, and how did we get to present day, an era of writing?
Dr. Church: Oh, thank you, Rhonda. Let's see. Let's start with...I think we didn't realize that we were on an exponential when we started sequencing. I got introduced to it through RNA sequencing. There wasn't DNA sequencing. And then Wally Gilbert was my mentor as a graduate student, and he and his team invented it in 1977. Independently. Fred Sanger published a paper that same year.
It took a little longer for the Sanger method to get implemented. But what happened was, very quickly, we got to a point where we were talking about doing a whole genome, mainly at the Department of Energy's bequest, in 1984. They asked a harder problem, which was, how do you estimate mutation rates to the consequence of energy? And we felt...you know, a handful or maybe 10 scientists in what would later be called genomics said, "Well, we can't do that, but what we might be able to do is get one genome, a reference genome." That consolation prize was big enough that Charles DeLisi at the Department of Energy just started writing checks. I mean, he didn't wait for an act of Congress or anything, just had money for this kind of R&D because of health effects. And then it took about three years.
I was transitioning from postdoc to professor, and my lab got one of the first two Genome Project grants. And then the NIH...it took about three years before the NIH got involved, but they got involved in a big way because they felt they were a more appropriate vehicle for anything health related than the Department of Energy. And they did it, kind of, in a teamwork with maybe 30% DOE and 70% NIH in the United States component, plus lots of international collaboration, really starting in 1990 with a 15-year goal.
There was a lot of talk of cutting corners at the beginning. I didn't necessarily call it that, but there was a lot of people trying to do 1X coverage, meaning doing every base pair...reading it exactly once. And I didn't like most of these corner-cutting things, but I was the most junior member of the project from the beginning. I didn't have a lot of sway.
I also felt that we should put technology development upfront because that could reduce the price, and then we could do a lot more than one genome for a lot less than $3 billion. As soon as some of the senior members of the visionary team, like Jim Watson, who came in later, started representing...drumming up support in Congress, it became evident that we would have $3 billion. And then the motivation for bringing the price down disappeared for a few years...a decade.
Then instead of...some of the corner cutting was to not worry too much about the repetitive sequences, which in the case of the fruit fly was about half the genome. Yeah. You know, it doesn't matter. And at one point, they were going to just do the coding regions, which is 1%. It turns out, we still haven't identified the 1% coding regions that would not have been a shortcut. So a lot of these shortcuts were really ill-conceived. But fortunately, we did get a decent 92% of the genome and declared victory. I want to make sure we've got that before we go on to writing genomes. That's a whole another topic.
Dr. Patrick: Do we need more reference genomes? And what are your expectations of finding new tools elsewhere in the evolutionary tree?
Dr. Church: Well, so, yes, we certainly need more genomes. It's not just the reference. It's the population variation that's important. The variation is at least as important as the reference, and it helps us make sure we've got a good reference. So you can call that the reference. It is growing recognition that we can represent the reference as a diversity.
We are finding tools in the genomes. One of the nuances that developed, the first kind of recommendations for maybe 1984, 1985, 1986 was the Human Genome as if there were one and as if there weren't any other genomes. And I kept advocating for genome comparisons because, when you compare two genomes, that's almost as good as an experiment, but it gives you a richer formulation for exploration. And we have...part of that genome comparison has resulted in new tool discovery, and so it's kind of a positive feedback loop. You sequence some genomes, you find some tools, use those to read and write genomes, find some more tools, and so on.
I don't know where that ends, but I do think that synthetic biology is probably ultimately unlimited, while the diversity on earth, even though it's vast, is more limited. Almost by definition, we can explore more than currently exists, at least initially in narrow corridors, where we're looking at, you know, specific tool-building ecosystem, restoration, and medical consequences. I think there's a rich field of...let's say you had one book, and that's the only book you had. You could read it and reread it and reread it, and you keep learning more and more. But as soon as you start writing books, now you've got millions of them. That's how I think of the synthetic biology or writing of genomes.
Dr. Patrick: I've read a quote...kind of reminds me of the quote that I read from you that stated, "I have speculated that essentially everything that we can currently manufacture today without biology, we will be able to manufacture with biology and with potential advantages. Biology is intrinsically atomically precise, and it's scalable to cover the whole planet essentially for free." That's pretty revolutionary, I mean...
Dr. Church: Yeah. That's accurate reflection of how I felt then and how I feel today. Why is it reasonable? They are atomically precise. Biology does not yet gracefully use the entire periodic table or all the chemical bonds that you might want to make out of that periodic pairs of elements. It comes pretty quick...pretty close. It uses a lot of inorganic bonds that might surprise some people.
There are biological systems if you look widely enough. And now we're not talking about necessarily, you know, your enzymatic tools, which might have been implied in the previous, but, you know, all the things that...all the chemistry and physics that biology uses. They can make things that are fiber optics like and sponges. You can make semiconductors, ferromagnetic materials that help like compass. There are all kinds of dichroics and gratings that generate colors, you know, and the list goes on.
Materials that are used, either naturally or where the enzymatic apparatus that is used actually can...if you give it a new set of elements, it will incorporate those. You could say misincorporate them. But the point is they're atomically precise in that you can reproducibly make a molecule with thousands of atoms, and the next molecule over has exactly 1000 atoms and exactly the same configuration, you know, off by less than an atomic bond in length.
This is not something that happens in Silicon Valley or other, you know, worldwide manufacturing of silicon-based circuits or any other inorganic circuits. It is so far unique to biology. Another thing that's unique to biology is ability to replicate, so you can make a copy of yourself. So to make a copy...you know, the idea that a cell phone can make a copy of a cell phone is ludicrous so far, but there might be a use of hybrid system where we use biological inspiration...electronics inspiration to make hybrid devices that can replicate use of the full periodic table and do, you know, a few things that electronics is a little bit better at, better at telecommunications at certain wavelengths, very hazardous wavelengths like X-ray and gamma, as well as the other end of the spectrum, the radio.
Dr. Patrick: Let's talk about how writing the human genome may help us better understand it. So Francis Collins described the working draft of the human genome as the first glimpse of our own instruction book. But today, many scientists believe that to truly understand the instruction book, we also have to write it. Can you explain why that is?
Dr. Church: Right. Well, I'm not sure I would say, have to, but it is certainly very advantageous. I should mention that we don't even have the full instruction book of any human being yet. We declared victory in 2001 on a kind of a rough draft of 92%. Actually, it was considered the final draft of a rough draft in 2001. It was final draft in 2004, but it was still haploid, meaning it was just one genome, while all...essentially, all of us are diploid, inheritance from mother and father, except for our gametes. So, the sequence we have, the one human genome that we have is not of a gamete. It's of a strange haploid cell.
But that's not the big barrier to understanding. The big barriers, as you say, is...in order to understand how something works and also in order to develop new technologies, you need to be able to write and edit and alter. And you understand it because you'll say, "Gee, I have no idea..." It's like reverse engineering electronic circuit or some software. "So I have no idea what this code does. Let's change it." And then you say, "Oh, that changes the calendar. Okay. So then that code does calendar." Or in case the biology, you'll take a piece out, and now it no longer handles, you know, glucose. So you say, "Okay, that's part of the glucose monitoring system." And you can just get through that, and you can get to more and more nuanced changes for discovery's sake, but it's often entangled with not just discovering, but making useful synthetic biology. You'll have a challenge that you'll have out there, and that will drive the reading and writing technology forward. It will drive our creativity in terms of how these things can positively influence society and ecosystems.
Dr. Patrick: What's the goal of writing a large or a whole genome or an entire chromosome?
Dr. Church: So there are a few ideas that have come up, where something at a genomic scale is more desirable than a single gene. So a huge fraction of recombinant at the end, so the GMOs and synthetic biology, historically has been changing one or two genes. It doesn't make sense to synthesize whole genomes if you just want to change one or two genes. But more and more, we're seeing advantages of changing so many genes. You might as well rewrite the thing.
As an example of that, we have a project to change the genetic code to make any cell resistant to all viruses. And we just published a paper where we think we did that. And the way that it works is that the virus...all viruses, as far as we know, depend on the host genetic code, the translation ribosomal machinery. You can change the code without hurting the host. The host could be a cell. It could be an organism. So far we've only done it in one industrial organism, E. coli. But anyway, if you change that enough, the virus can't mutate. There'd be too many changes that are required to get the virus to be back to its healthy state.
And we think that this is completely general in that, essentially, every plant, microbe, and animal on earth, shares a very similar genetic code to one another, and in any case, have a genetic code that they share with the viruses. And if you take it offline, change it enough, like sometimes as few as two codons, let's say two codons, a code for serine, leucine, and arginine are our favorites ones because they have so many codons for each. They're triplets of ACG NT, so like AAA codes for lysine, the amino acid lysine. There's 64 of those, and if you change one, you get a new genetic code. If you can change two, and now you get something that's multivirus resistant. So that's an example where you have to make so many changes, tens of thousands of changes genome-wide. And they're interspersed throughout the genome. You might as well just synthesize it, and that's what was done.
Another example is of the extinction. There are a number of changes you might have to make in order to bring back some physiology like cold resistance and all the traits that go along with cold resistance, may be scattered around enough that you're...you can think of it either as highly multiplex editing or as a complete rewrite. And even when you do a complete rewrite, you're not changing every single base pair, all 3 billion times 2 bases. You're leaving them mostly intact. You've chemically synthesized it, but it's still useful to think of it as a lot of edits.
The maximum number of edits we've done by editing, meaning having an enzyme that's targeted at a particular place, is 24,000. The maximum we've done by synthesis is almost the same amount, although we have synthetic projects which are now getting close to done at 60,000. But then we're going to take the editing up to a million pretty soon. They go back and forth. There's a technical leapfrogging that goes on between editing and writing of genomes.
Dr. Patrick: This, sort of, moonshot goal of changing genomes or writing large genomes in a way writing, editing them, where, you know, as you mentioned, you make let's say...you take a human cell in a Petri dish, make it resistant to viruses or, you know, make it capable of synthesizing essential micronutrients that we usually have to get from our diet. Like, even if it just sits in a Petri dish forever, and that's the only place it goes, to me, there's something very just fundamentally, you know, awe-inspiring about that. Is it, kind of, like, along the lines of your thinking with doing some of those things?
Dr. Church: Yeah. I think the community, the synthetic biology community has responded in the same kind of awe-inspiring the initiation of this kind of project. I hesitate to call it a moonshot because I actually think the moonshot was not as inspiring to me as the satellites, the GPS satellites, the weather satellites, and, you know, surveillance of land. And the same thing goes for other big projects.
The Genome Project wasn't as impressive to me as reducing the cost project, $1000 Genome Project, sort of, the technology development. And the Manhattan Project was certainly not as attractive to me as say the projects for nuclear fusion, which could have...all of these things could have started much earlier on. They sound may be a little bit harder, but what they have in common is they're very much more consciously aimed at positive societal consequences. And I think it's a little easier to get everybody excited about these, sort of, things.
And I think being able to make industrial microorganisms, plants, and animals are important for ecosystems and agriculture and human stem cells. They won't stay in that Petri plate. They will make their way into cell therapies in humans. And if we're going to fix something that's broken that you can fix with blood cells, you might as well have those blood cells be resistant to all viruses as well if that is shown to be safe and effective by the FDA and similar organizations.
Dr. Patrick: You, kind of, alluded to this earlier, but how do you think the Vertebrate Genomes Project will affect the field of genetics and biology?
Dr. Church: So the Vertebrates Genome Project, I think, is just indicative of our wish to sequence the whole biosphere. Vertebrates in particular are helpful because they often constitute keystone species in the wild. And I hope...I think there's a reason to believe that we will be restoring more and more of the non-urban environment to wilderness. Certainly, you can see about 1000 successful rewilding projects, a local rewilding. So, the most famous one is probably restoring the wolves to Yellowstone after 70 years. They had a typical keystone effect. That ripple effect was anticipated and worked out, which was they changed the abundance of large herbivores, which then changed the abundance of the willows and other trees, which changed the beavers' behavior which changed the lakes, which resulted in aquaculture. So just introducing one vertebrate had all this ripple effect. That's one reason to do it, but there are many others.
And if we are causing the extinction of many species, we are also causing the hybridization, which is the creation of new species. It's not clear that we're making extinction faster or more significant than hybrid than new species. I think our gut feeling is that we are, but it's not proven yet. But in any case, we need to do that survey to see in detail what we're doing, and in some cases, we need to freeze away as many organisms as possible. But we shouldn't be confused that freezing it away or putting it in a database doesn't mean that it's going to be easy or even possible to restore. We need to do everything. We need to document, freeze, and protect what is already there by shrinking our agricultural use possibly by, you know, 10 or 100 fold. I think that's totally feasible to do with synthetic biology and other new tools that we have.
Dr. Patrick: Can you talk about the advantages of perhaps computer-aided design of genomes, the, sort of, aspirational software, heart and soul of the Genome Project, right? So in particular, I'm curious about advances in AI like those coming out of DeepMind such as the AlphaFold, and if they have special relevance for this, sort of, complex work.
Dr. Church: Right. So the genome consists of, 1% of it codes for proteins, and an AlphaFold is focused mostly on the proteins. There's some software for folding RNA and folding even the genome itself. That can either be predictive or it can be measured. So there's a lot of software that's used for looking through microscopes and determining the structure and try and correlate that structure, again, by synthetic biology. You say, "Let's change the shape, not just the sequence, and see how that...see what function that affects." And that trial and error can go very quickly or even exponentially. Once you get going, you see the patterns and you start testing more and more sophisticated hypotheses.
But AlphaFold is not the only way to do it. So there are other machine learning-based methods, in fact, machine learning plot coupled with multiplex libraries, which can be in the millions or billions of synthetic molecules that act as...there are subtle variations or sometimes not so subtle various ones together. If you do machines and everything plus mega libraries, you're focusing on functionality rather than on structure. AlphaFold predicts a 3D structure. And to illustrate this, you have...let's say you take a serine protease. It's called a serine protease because there's a very key serine right at the active site. And that serine has an oxygen that's part of the mechanism. If you change that oxygen, that hydroxyl to a hydrogen, it now becomes an alanine, and it's completely functionless. But the three-dimensional structure is completely preserved. It is atomically precise throughout the structure, but it's a dead enzyme.
So what's more interesting, I think, for most practical applications is studying what functional consequences are of substituting. And that applies not just to proteins, which AlphaFold predicts, but also the RNAs and DNAs. You want to know what the landscape of functionality is. And that can be done partly by phylogenetic evolutionary trees, where you line up. We now have tens of thousands of examples of almost every major macromolecule in the cell, proteins, RNAs, and DNAs.
And then using that, or you can...if you feel that's not enough that evolution hasn't provided you with enough diversity for your machine learning, you can generate your own data set. So, when they were learning chess, and Go, they would have the computer play these games against itself to generate more data. Big data is good in the case of machine learning. And in our case, we use these mega libraries, these millions and billions, even trillions, that act as a kind of a wetware computer. It can do all this computing, and you can read it out in terms of the sequencing that you were talking about earlier and barcodes. So you can barcode all these molecules and combinations of molecules. And so you can think of these synthetic biology libraries as an honorary computation device, what you use together with the machine learning, which is typically done on a classic von Neumann machine, meaning an ordinary kind of computer that most of us would recognize.
Dr. Patrick: In your opinion, how has the idea of biology as a software, reading, writing, programming, and debugging, sort of, held up over time?
Dr. Church: Well, metaphors are imperfect. I think the advantages outweigh the disadvantages of using these metaphors. I'm a programmer since, you know, the mid-60s as a pre-teen, and I've been programming both computers and biology. And I find that the metaphor really works for me personally.
Where it breaks down a little bit is when you say that your goals should be set by the goals of the metaphor, in other words, that in the early days of synthetic biology, there were multiple camps. And one of them was the camp where we're going to have "AND" gates and "OR" gates, and "if-then-elses," and all the Boolean logic that might characterize a certain category of computation electronics.
And I felt and I still feel that there's a lot to be...a lot of interesting biology that occurs with analog circuits. And we've kind of lost track (or some of us) have lost track of that key component of electronics, but it is there. But anyway, the analogs, there's the evolution, where you, - typically, when you make a cell phone, as far as I know, you make a very small number of prototypes that are very similar to one another, and you test them out. But in biology, like I've said a couple times now, you can make billions and trillions, and you can do accelerated evolution, while with most, you know, bridge building and building trains and jets and cell phones, you really don't have that luxury of making trillions of them and seeing which one works best.
Dr. Patrick: How fast is the field of synthetic biology advancing? Are you excited about where the field's going? Do you have any concerns or fears?
Dr. Church: Yeah. I would say both excitement and concerns. And I think that applies to all technologies. I think that we need more radical and just... You know, it could be positively disruptive, but you have to think of all the potential negatives. So, it is happening exponentially. How fast? It's doubles at least once a year. Sometimes we'll get a factor of 10 per year as measured by both reading and writing DNA. Most of the 10, 20, 30 million fold has occurred within the last decade or two. So it's potentially faster than Moore's Law for electronics. And it has, kind of, this atomic limit that's very comfortable programming precise atomic positions using biology. Now, those sorts of tools we've got. We're getting more and more.
Now, on the negative side, we need to be...we have good government agencies that we should be very supportive of, both intellectually and financially like the FDA, the EPA, the USDA, and their foreign equivalents. These are not sufficient, though, because they're things like equitable distribution of technology. We want everybody on the planet to have...at least have a chance to, not only theoretically have access to because the price is right, but also have the education or the dialogue that allows them to evaluate whether they...to know that it exists and to evaluate, what, they want to use it or not and whether it's good for them.
So, it's not sufficient to just, like, lob over a free piece of software like, you know, GPS software, and they don't know what the satellites are doing and so forth. Now, modern uses of GPS like Google Maps is fairly accessible, but there's almost no technology that's completely equally accessible. You know, clean water, roads, you know, cell phones are getting accessible in remote parts of the world. The only thing that is truly accessible equally that I can think of offhand is a biotechnology, and that is smallpox. It's completely extinct, and so you don't have to constantly be bringing out a new drug or a new vaccine that maybe not everybody can afford, every government can give out for free. But smallpox extinction is something we can give out for free generation after generation. So, I'm looking for more and more of those. You know, bringing down the price of reading and writing DNA by 10 million fold is just a start. We should look for that in almost everything we do with synthetic biology.
Dr. Patrick: Do we need the NIH to embrace the Human Genome Write Project like they did the read? Or is that, sort of, already happening?
Dr. Church: I think it would be lovely if they did. I think we need to pursue multiple routes, philanthropy, industry, government, multiple...again, having DOE and NIH in the game was helpful, but there's a number of others that are interested in the Genome Project Write, NSF, ARPA, DARPA, and IARPA. And these have supported it in various forms, have supported synthetic biology, Genome Project-write, has, yeah, been...it's the heir of all those wonderful funding sources.
As long as it has a vision that includes something that is net positive for society, there will be a way and hopefully multiple different ways for different flavors of it. One of the early flagship challenges is this resistance to all viruses in multiple organisms. I think that's something that can be clearly articulated, and it has, I think, a much higher positives and negatives. And most of the negatives, I think, we can mitigate by thinking of all the possible downsides and how to protect against them.
Dr. Patrick: Let's take a dive into some of the gene editing tools and whatnot a little bit. Over the last 10 years since Jennifer Doudna and colleagues first developed CRISPR gene editing, there's been a lot of excitement about it. Your lab was one of the first to show that gene editing using CRISPR-Cas9 could be done in normal human cells. So acknowledging the undoubtedly, like, revolutionary impact of CRISPR, do you think it's possible it's been overhyped from the standpoint of the public at large not having a more comprehensive or appropriate understanding of where it, sort of, fits within the existing toolsets of synthetic biology?
Dr. Church: Yeah. I hesitate to use the word hype because it implies somebody is being hyperbolic. It was kind of a team effort of...it's wonderful that we're bringing it, any part of reading and writing genomes in synthetic biology to people's attention or science, for that matter. This is one of the more exciting things in science right now is getting people... It's not just about CRISPR.
First of all, you can't really edit if you can't read. So I think the big revolution here is being able to read the genomes. You read them at the beginning to find the tools. You read them again to decide what your goals of editing are. And then you read it a few times to make sure your editing is going well. Then you read it again to see that the edit that you made has the physiological consequences, which increasingly we're using DNA reading as a way of or RNA reading to see how the physiology is going, the so-called epigenomics for physiology. So, that reading is important.
Another thing that's important is there was some pretty good editing methods that are still in use to predate CRISPR, notably homologous recombination, which Smithies and Capecchi got the Nobel prize for decades before Jennifer and Emmanuelle. I'm a big fan of Jennifer and Emmanuelle, by the way. We've started a few companies together, Jennifer and I. But there's homologous recombination, which is very powerful. It's precise and over large distances, while CRISPR tends to be imprecise and/or small in scope.
Another one that dates back two decades before CRISPR is SSAPs or lambda red as it's sometimes called is a way of getting precise editing. And that's what we actually used to...around 2009 to make libraries of billions of edited cells in a day, a single person. That shows some of the power. And the other evidence of its power was that that was...the first completely recoded genome was done mostly a combination of SSAPs and recombinases, which is also very precise. CRISPR was basically a hatchet, and I sometimes call it genome vandalism.
So, I think we need to embrace all of these methods and a few more that are coming now, deaminases that can be done with and without CRISPR and more sophisticated SSAPs and integrases, transposonases. So, it's a rich... I think it's okay if the public just latches onto one aspect of it, but it'd be nice...it is nice whenever a more nuanced and visionary form where it illustrates the importance of reading and other more precise and larger scale editing and writing where you write...synthesize something from scratch, and usually pop it in by some...it could be popped in by CRISPR but more commonly is popped in using recombinases or integrases.
Dr. Patrick: What about some of the existing capabilities of, you know, gene editing therapy, you know, things that have been done, you know, in transgenic models for, you know, a decade at least or more, you know, so deleting versus addition, you know, of a missing gene?
Dr. Church: Right. Yeah. So, you can think of CRISPR as a subset of editing. Editing is a subset of genome engineering, and genome engineering is not a subset of, but it's kind of a Venn diagram overlapping set with therapies and GMOs and so forth. So, most gene therapies that have been approved are adding genes, and this is done typically without CRISPR.
And, you know, when you have a genetic disease, you're missing a gene, so you don't really want to edit necessarily. You want to add it back in. As you grow older, a lot of your gene products...your gene expression is dropping down. One way to deal with that would boost it back up, and we've explored these sorts of things.
The use of gene therapy, putting in a missing gene, and, in fact, editing for that matter for rare genetic diseases is by its nature expensive. It's millions of dollars per person over a lifetime, partly because the R&D costs and the palliative care and all sorts of health care for someone who has a very severe disease that might have died young years ago, but thanks to the Orphan Drug Act and others, they can now lead closer to normal life but at millions of dollars.
It's great that we'll keep developing these gene therapies and better ways of delivery. Oh, I forgot to mention, delivery is another thing that's sometimes missed when people just shout CRISPR. You have to get it to the right place, the right dose, the right time, maybe to turn off when it's done its job. So keep it off target...keep it off target, so minimum. So anyway, the delivery.
An alternative to this expensive solution is a much lower cost one, which is genetic counseling, where you basically tell people before they get married, before the preconception or sometimes post-conception, that they're at risk. They themselves are carriers. They are healthy. They will be healthy. But if they marry someone that has the same carrier status, they put their children at risk. So there's the two methods.
I think a lot of the Western world tends to go towards the interventionism, you know, reactive medicine where we'll spend millions of dollars, you know, by not pursuing preventative medicine. But the preventative medicine, in this case, is, you know, low hundreds of dollars just to know yourself to know how to keep your children healthy by making preconception choices.
Dr. Patrick: Yeah. I will probably circle back to a little bit more of that in a minute, but since we're talking about...you mentioned a few other types of, you know, gene editing, the deaminases, and you've talked about this multiplex editing. What does it mean to be able to go, you know, to performing 26,000 edits or you said, I mean, a million...potentially a million edits in human cells, you know, versus the previous record of something like 62? I mean, what applications does this most impact? Is it, you know, the large genome creation or tissue engineering or germline?
Dr. Church: Right. Our previous record of 62 or 42, depending on how you count it, was in pigs, and it was for tissue engineering. It was germline. So germline is kind of off the table for humans, in part because there is no clearly articulated medical need, and the time for discovering safety and efficacy is over a lifetime which is, you know, unaffordable and ill-advised. So anyway.
But germline certainly work, gets into humans via pigs. This has been...the idea of transplanting organs from animals to humans goes back at least to the 1960s, where a chimpanzee kidney survived for nine months in a school teacher who went back to teach and, you know, was normal for nine months. That was the exception then and it would be the exception now except for the synthetic biology that we do on the germline of pigs, which now made it into many pre-clinical primate transplant trials, pig-to-primate, and a few pig to human trials that are going on.
Primate survival looks like around 600 days so far, and they're still...a couple of them are still alive at 500, 600 days. We're going to keep improving these. That's in the order of 40 to 60 edits per genome in the germline. The multivirus resistance requires more than that. Some things that are done for diversity and ecosystem maintenance may involve even more. They're a type of tape recorder, something that's called a flight recorder, so it's analogous to planes, that record a lot of data. But typically, you don't read it, so a lot of writing, not much reading, unless the plane goes down. Then you'll look at selective regions for debugging what went wrong. That same thing could be put into the bodies of plants, animals, and even humans because it's a very compact reporting device of the physiological states of every cell in the body.
We've shown this works, sort of, in the scale of 60 to 24,000. That's probably...our first effort at making a million edits will be in the form of these molecular flight recorders. So those are a few examples, but the number will grow as soon as we get more than a handful of people working on these visionary projects. But we'll see a blossoming of all sorts of creative uses of making multiplex editing. I think non-multiplex editing will become the exception.
Dr. Patrick: So as you mentioned your lab, you know, gene-edited pigs, and you enhance them by making them resistant to some retroviruses. Do you think, you know, as a more visionary, kind of, question, that you could use, you know, more precise gene editing, the deaminases or CRISPR, whatever, to eliminate viral spillover events from livestock to humans? So, I mean, there's a lot of viruses that originate from livestock when we're raising animals in captivity.
Dr. Church: Yes, this is important. The viruses that we got rid of were endogenous retroviruses, meaning they're built into the pig genome of every pig on the planet. And they have been shown to infect human cells and to replicate and go into other human cells. So this is particularly bad scenario in immune-compromised patients. And the FDA recognized this decades ago and really was, I think, pleased to see progress being made on eliminating them from the germline of the pigs.
But in addition to viruses that are built into the germline of animals and humans, there are viruses coming in from outside. And we just published the first example. This is with Luhan Yang's team. She was a graduate student and a postdoctoral fellow in my lab and co-founded eGenesis and Qihan for making cell therapies and organ therapies. But anyway.
As a side project, we published a paper on getting rid of African swine fever virus by making CRISPR to attack the viral DNA. What CRISPR originally evolved to do is to take out bacterial viruses. We think this is the first case of using CRISPR in a practical sense for eliminating mammalian viruses from the environment. It's using CRISPR against mammalian viruses.
But zoonotic diseases is bigger than that. If we could make a huge fraction of plants, animals, and humans resistant to those viruses because of their genetic code, that actually anticipates viruses we haven't even seen yet. It should handle all natural viruses, so like, you know, Marburg, Ebola, HIV, CRISPR. These would not have been surprises. They would have been surprises to scientists but not to this cancer resistance...sorry, virus-resistant cells.
Dr. Patrick: So it sounds like CRISPR seems to be uniquely positioned for that, you know, type of use.
Dr. Church: Well, not necessarily... so I like CRISPR. I love CRISPR. I personally benefited from it, but it is...I like to balance it. There are other nucleases that some people claim are more specific, less off target. There are deaminases that don't involve CRISPR. So I wouldn't say...term unique is too strong. We have a lot of tools in the toolbox. A lot of it has to do with delivery and testing too. Testing is a big deal, which is somewhat swept under the rug when we're just...it's just like, "All we have to do is design, you know, CRISPR to take care of everything." But there's a lot of reading and, you know, synthesis which isn't CRISPR. And then the delivery and testing. So it's integrated whole. It doesn't require CRISPR.
Dr. Patrick: So another technology would be base editing, which, you know, doesn't involve double-stranded breaks and DNA. And I know there's a phase 1B trial with the PCSK9 target. They're targeting at gene target for the liver as a potential treatment for the hypercholesterolemia familial form. You know, I just read about this recently and pretty excited. You know, I know people that are taking the anti-PCSK9 antibodies, which are very expensive, and you have to get them every two to four weeks. It'll be interesting to see, you know, if the base editing could be a one-and-done treatment, do you think?
Dr. Church: That is one of the advantages of gene therapy in general, whether it's editing or adding genes. Yeah, I think that a lot of our diseases are diseases of wealth. I mean, we used to have much more active vegan diets, you know, low in overall carbohydrates mainly because it was low in calories altogether. And so diabetes and some of the cardiovascular diseases didn't affect us. Also, we didn't live as long in general. So it was less of an issue.
But PCSK9 is...it looks like it's shaping up to be a terrific example of something that basically all humans can be thought of as having the same disease, and therefore it's a large market could be low cost. Aging is another or a variety of age-related diseases that might have a common core where we are programmed to die at a certain age. The mice diet at two years old, bowhead whales at 200, humans somewhere in between. And so that's probably negotiable.
Now, PCSK9 is not solving aging in general. It's a very specific thing that may be common to most humans. It was de-risked because there were a few humans that were walking around that were basically double null for both copies of their PCSK9 from mom and dad. That kind of showed us that it was going to be safe and effective, although there's still quite a bit of long-term studies that have to be shown to make sure it doesn't cause early onset neurodegeneration in the particular way that we're implementing it, which is not germline, which is how it...the people that previously had PCSK9 nulls for germline via natural mutations.
Dr. Patrick: Since you mentioned aging, it sounds like...and I think you think aging is fundamentally a program. It's a really interesting idea, one that's probably...it's got many implications, especially when we're thinking about whether or not we can mitigate aging or potentially cure it. So could you talk about your perspectives on that, what you think it might mean for the future of human aging?
Dr. Church: Well, so what we're mostly aiming for is serious diseases of aging. They may have relatively little in common in terms of what organ is affected, you know, what system. There may be 9 or 10 different pathways that can be affected, the so-called hallmarks of aging. So it's a great diversity. There is a school of thought that they have a small core set of systems biology, systems medicine that if you get at that core, you can change the clock. You can make it shorter as in mice or longer as in bowhead whale. And then you can rejuvenate. There is rejuvenation that occurs whenever you go through gametogenesis and fertilization, sort of, normal reproduction. You reset the age clock, and you also reset it when you do something unnatural, which is cloning where you take the nucleus from an old animal and put it into rejuvenating environment of an egg.
And there's also a rejuvenation process that occurs unnaturally when you use transcription factors. These are DNA binding proteins that regulate the expression of genes. Four of them so-called Yamanaka factors or OSKM as an abbreviation. These will very convincingly take a very old cell and turn it into a very young cell, maybe like, say, a skin cell from 80 year old. It will take on many of the characteristic...most of the significant characteristics of an embryonic cell in that it can produce almost all the tissues of the body, probably all of them, except for the extra-embryonic. And the parts aren't part of the body that contribute to the early embryogenesis.
So those are a few, and there are many others that shown that the blood...what's in the blood of older and younger animals can influence one another. The older blood makes the younger ones old, and the young blood makes the older animals younger by a variety of biomarkers and disease-related things.
I fall into the...there's two schools, at least two schools of thought here. There's a damage school where you have to go in there and kind of micromanage a surgery to fix the damage as your surgeon might fix a damaged broken arm. Then there's the epigenetics school where it says that if you convince the cell that it's young, it will fix itself to a large extent. There will be some exceptions. And we've seen that over and over these, you know, fertilization, cloning, and OSKM factors are three. Again, the bloodborne factors are four examples.
And we need to reset all of the mechanisms, all nine hallmarks of aging in probably all of the tissue types of the body, at least the stem cells for each of the body parts, to have a shot at...we're aiming for youthfulness, lack of age-related diseases, so you should be youthful at an age where you normally would be unhealthy, even if you're not dying of any particular disease. That's what we're aiming for. It will be approved by the FDA for specific indications for specific diseases of aging.
But then if it really is getting at the core of aging, will it be immediately applicable to almost all of the diseases of aging? And aging just affects everything, almost every morbidity, mortality, even like accidental death. Infectious diseases like COVID has a very...and its cognitive consequences have very steep increases at around 60 years old.
Dr. Patrick: So I recall, like, one of your former publications. I forgot what year. I think it was a PNAS one where you did gene therapy and added three transcription factors to rodents, to mice, and there was some reversal of aging or biomarkers. And it was a TGF beta receptor and FGF21 and...
Dr. Church: Alpha-klotho. Yeah.
Dr. Patrick: Klotho. Yeah.
Dr. Church: Those were not transcription factors. Those were soluble factors.
Dr. Patrick: That's right. Okay.
Dr. Church: But we also did a separate experiment where we took three transcription factors, OS and K, of OSKM, separate experiments, but delivered in similar ways, adeno-associated virus. Then we did some other experiments with follistatin and telomerase, so it affects the ends of the chromosomes, the telomeres. Follistatin is mostly muscle.
But each of these has, you know, reproducible impact on hallmarks of aging, on biomarkers of aging, and diseases of aging. And it affects multiple diseases with about seven different categories of diseases that we've done now in mice. A subset of those have been tested in dogs now, aiming for a veterinary product.
The three that you mentioned, I think, have slight advantages, the fibroblast FGF21 and TGF beta. I should mention, that is an...the other two are natural alpha-klotho and fibro FGF21. But the TGF beta receptor is normally membrane-bound. We made a soluble form of it. So all three of them tend to be soluble, and they effectively act like the young blood in rejuvenating these mice and dogs, and hopefully, soon there'll be in human clinical trials. And that has the advantage that we don't yet have a good way of delivering to every cell in the body or every stem cell in the body. Remember I said delivery was very important and it's so important. We need to fix it.
But anyway, in the meantime, we can deliver the genes to a subset of cells in various parts of the body, and then those subset will deliver the proteins, those three proteins you mentioned, more broadly. And so you can, in principle, affect the whole body by that combination of two kind of tiers of delivery. That's the idea behind that. And the dogs is a particularly good conduit to humans because they're large mammals like humans. They live often in a human environment, eat humans...like sometimes eat human food. They have similar kind of emotions and bonding and eye contact and all the rest. And the owners can really sense their states so they can get at more subtle, positive and negative consequences earlier. So anyways. And it's a product now that people care deeply about their pets. So, I'm very excited about, you know, Rejuvenate Bio, and Noah Davidson was a postdoc in my lab, and he started Rejuvenate Bio. It seems to be shaping up to be a good product line.
Dr. Patrick: Yeah. It'll be exciting to follow these results. You kind of answered one of my questions, which was, you know, a lot of the rodent research, particularly with aging, not a lot of it translates, you know, to humans. And, you know, one thing, in particular, I think, that is important to consider with human aging is that, you know, humans are exposed to disease and viruses. We're not in this, like, sterile lab environment, and we have these periods of real, like, illness and muscle disuse, and it's just very different than a rodent. But there's advantages to studying...to using rodents. What do you think? Why should we use rodents to study aging?
Dr. Church: So, as a prelude to the experiment that you mentioned where we use three soluble factors in dogs, we did 45 different gene therapies singly, one at a time, in rodents, mice to make sure...to find the subset of three that we wanted to test in rodents in combinations...various combinations. And then once we had settled on the 3 factors out of 45, then we moved into dogs, and then we'll next move into humans.
So, you shouldn't blindly expect the rodent model to work. They're advantageous because they only live two years, so it's easy to see a longevity effect. We're not always looking for longevity. We're usually looking for aging...reversal of age-related diseases because that's what the FDA wants as well. But we do occasionally measure longevity in the case of the follistatin and telomerase treatments. Those did show a pretty significant...very significant longevity effect on the rodents.
So, even primate trials can be deceptive. There's a lot of differences in the way that they're treated. In fact, in certain ways, dogs have, I think, a more similar environment, maybe, you know, more to their liking, more natural for them since they've been our companion for tens of thousands of years. But even dogs are not an ideal of larger... You know, pigs are very close to humans and their organs. That's why they're being used as transplants, but they're also imperfect.
So an alternative to all of the animal models is human organoids, and those are getting increasingly accurate. Also, we can basically skip a lot of the developmental biology and go straight to a particular organ. We can't go via normal human development because there's a ban on letting human embryos develop past 14 days in a dish. But it's considered ethical to make an isolated heart or even heart plus lungs, plus muscle, plus liver, plus neurons, but not a whole brain. As this is rapidly developing, we're exploring collectively with diverse set of voices, you know, how to do this in a way that's humane to the animals or develop all...you know, completely animal-independent strategies for both testing therapies, but also being the therapies.
The organoids are increasingly moving their way into clinical trial. So for example, we showed restoration of a demyelinating disease in rodents by putting human organoids, brain organoids that contain...that remyelinate and are protected against the demyelinated mechanisms. So they're supercells and that they are not just replacing the cells that were damaged because they just get damaged themselves, but they are resistant to the damage. And I think that is repeated over and over again in both cell therapies and organ therapies we're developing, is that the goal is not just to deal with the organ shortage or it's to have something that's enhanced is immunologically superior that is less rejected, resistance to pathogens, resistance to cancerous senescence, cryopreservation. All of these things have been demonstrated in animals, and now we want to either get them into the humans via cell or organ transplants.
Dr. Patrick: If I remember correctly, you enhanced the brain organoid to...I think you edited it from APOE4, which if you're homozygous, you have like a 20-fold increased risk for Alzheimer's to APOE3, so making it more resilient against Alzheimer's, I guess.
Dr. Church: Correct. So that's somewhat...depending on how you look at the composition of various genes, now that particular case E4 is not the predominant allele. And so you might call it an enhancement. PCSK9 is very rare in the population, and so if you make everybody or a large fraction of population PCSK9 negative, that could be called an enhancement relative to the average. But it's not an enhancement relative to the minority. In the case of APOE3 or even APOE2, which is...that is rare than the E3 plus E4, and that would be an enhancement. But E3 over E4 is probably about closer to average.
But this whole definition of or this whole obsession of an enhancement seems odd because a huge fraction of our popular technologies are enhancements, you know, a smartphone makes us smarter in a certain way. It can also make us dumber. But the point is it has the capability of helping us navigate, help getting access to the world's facts and factoids. Cars, jets, so forth enhance our ability to locomote.
So I think increasingly, we're going to recognize that the biotechnologies we're producing are not just reactive medicine where we're putting out fires. They're preventative medicine where we're...by enhancement, we're protecting ourselves. Like vaccines is a beautiful example of enhancement that protects us. We're far healthier than our ancestors were because of vaccines.
Dr. Patrick: I kind of would like to just move into...a little bit to the germline editing. We've kind of talked...alluded to it a little bit here and there. But you've said and previously that you felt like an obligation to be balanced. But you've also, of course, said it's important to focus on outcomes and not to rationalize addictions to future. And you're even involved in calling for a temporary moratorium on germline editing?
Dr. Church: No.
Dr. Patrick: No.
Dr. Church: I was opposed to the obsession with moratorium because we already have a moratorium on all new drugs. We don't allow anybody to use new drugs that haven't been through the FDA testing. So, yeah. So it sounds subtle, but I was concerned that we would be developing germline where there's no need. But there's also no need for a moratorium because we have very good regulatory mechanisms for preventing that, sort of, thing from happening at a market scale.
Now, a moratorium would not do anything more at the market scale and also would not do anything more at the individual scale. Both the FDA...and, in fact, most laws do not work on individuals that want to break the laws that are willing to accept the consequences or think they're above the consequences. And that's what happened in the case of germline. Someone either misinterpreted willfully the guidelines or didn't think it was a law. In fact, he didn't get convicted of germline manipulation. This is He Juankul from China. He got convicted of, you know, not following the rules for getting the consent of the funding agencies and the patients and so forth.
He actually did a pretty good job of getting the consent by some criteria. He spent an hour of videotaped counseling to make sure they understood what they were getting into. But anyway, as far as I know, he was not convicted of germline therapy, but something more nuanced. And he's out now. The three years is up and he's out. And as far as we know, the children are healthy, which is more than you can say for the most revolutionary new treatments. That's what I mean by balance is let's talk about what did he actually do that was harmful to the patients or harmful to society rather than just having a knee-jerk response. We were all coiled up ready to say that... He actually did try to pay attention to the ethics, but there wasn't a clear ethical consensus beyond the National Academy of Sciences report that I participated in a minor way.
He was trying to go down their checklist, but he was doing it, sort of, he's being the judge of whether he was doing the checklist right or not. I think that rubbed people the wrong way, and I think the Chinese government was very sensitive to what international opinion would be. It's not clear they would have acted quite so harshly if there had been no international backlash. They might have nominated him for a Nobel prize in a parallel universe.
Dr. Patrick: A couple questions come to mind there, I mean, the international reaction. I mean, the differences in the public response, you know, in 1978, the first...Louise Brown was the first baby born, was conceived by in vitro fertilization and considered one of the biggest medical breakthroughs of the 20th century. But presumably, at the time, it was quite controversial. And, you know, I'm just, sort of, interested in the public response to that, sort of, medical technology and use of it versus the CRISPR edited babies in 2018 if they were proportional.
Dr. Church: Well, I think that this concern about doing things that are unnatural happens again and again. And natural is often...is not defined as the way the world was before humans. It's usually...it's the way our grandparents lived. There's some kind of nostalgic of reification of the way our grandparents lived, even though we weren't there. You know, we just imagined that they had a perfect life without antibiotics or motors or that sort of thing.
So, what's natural is a moving target, and a lot of things that were demonized, villainized in the past are taken for granted now. You know, for example, some of us might remember how cell phones were demonized as melting your brain or, you know, giving radiation to your brain. But now people are on cell phones all day. They don't even use landlines anymore. And you could even say...so anyway.
You know, the response is one of caution, and the appropriate response is, we're going to cautiously take this to the Food and Drug Administration. But that requires that the government allows us to take to the Food and Drug Administration, which right now we can't do because a 2016 writer says we can't even allow the FDA to accept these nominations for clinical trials. So this is a very, you know, head in the sand kind of approach to science, usually that be careful. And most FDA trials are very carefully vetted before they go in.
Preventing that careful accumulation of data could cause lives. I don't think it's urgent. In the case of germline, no one has articulated a particular thing other than HIV resistance, which is what He Juankul did. I think was actually a pretty good choice of CCR5 and HIV resistance in He Juankul case. I think some people maybe don't appreciate how stigmatizing HIV can be in certain communities in China. Anyway, it's a complicated issue that I think we need to be respectful of both the potential future and the path...safe path towards it.
Dr. Patrick: How do you think we can equip people with the right knowledge in order to come to, you know, well-reasoned conclusions surrounding germline editing? You know, understandings of complexities. So we've got, you know, background mutational rate and offspring impact. I mean, if you compare it to, you know, again, a background mutational rate or a paternal chemo, right? You know, if a man goes and, you know, he has cancer, and he gets treatment, and then after the treatment goes off and has a child, you know, we kind of accept that, you know, mutational rate. So things that are known about germline mutagens, I guess.
Dr. Church: Right. I mean, chemotherapy is a perfect example, or the radiation you get living at high altitude. This falls into what I was saying about nature or natural, which is, you know, defined as whatever we've accepted... Whatever technologies we've accepted up to this point are natural and any new one. So chemotherapy is okay even if it's more mutagenic than gene therapy.
I don't think we necessarily have to educate people or establish what the right answer is. I think it's about conversation. Sometimes people say, "Well, you know, you need to, you know, reach out to everybody." Well, the thing is a lot of people you reach out to aren't particularly interested. They don't have the time to have a discussion about some abstract science that isn't in the supermarket. So, that's one issue. One way to make that connection, though, is with more common media like, you know, books and movies, television. These are things where you can put it in a framework, that's entertaining and educational.
You know, my wife, for example, contributed to the "Grey's Anatomy Genome Lab" episodes. That's one form of dialogue where they can say, "Oh, you know, we're worried about Jurassic Park." There's no reason to avoid the negatives. Some of my colleagues don't like negative painting of scientists in entertainment. But I think it's good. It protects us from, sort of, those scenarios and slight generalizations of scenarios. And the more we think of, the more we're protected.
I think the way that germline...if germline gets accepted the way that in vitro fertilization was eventually accepted. It was demonized too. The whole term, test tube babies, which we think is quaint now, was supposed to be scary back then in the 70s. Test tube babies, you know, it's like, that's totally unnatural. But now, you know, it is millions of...I think 6 million babies have been born that way, including some of my close colleagues.
So, I think the way it may make it into a popular acceptance so it's considered natural and the next thing is unnatural is number one is if we're already getting humans that are getting transplants from germline manipulated pigs. So if germline is not hurting the herds of pigs that are providing all these organs and it's not hurting the patient that's getting the organ, then maybe that's one way. The other way is we'll have more and more gene therapies that are somatic, not germline, but they're done at early age maybe to cure, you know, early onset childhood diseases or maybe even done in fetuses but not in germline. So people will say, "Oh, yeah, you can do it really, really early in utero. What are we really worried about?"
And some of these gene therapies as people start to get...to be quite old will say, "Okay, it doesn't have long-term consequences." And then somebody will come up with a use case that is very compelling or someone has a very serious medical disease, might be infertility, might be something more fatal than that, and then that will be the tipping point if there is a tipping point. Could be that has to do with something that we all share in common that's very hard to fix in adults. The problem is there are very few examples of that. You know, maybe space travel requires some effort in the germline, but even that, you know, we might be able to make every cell in the body radiation resistant. Maybe we can make some kind of multiplex edited solution to low gravity.
So, I think maybe we can make a multiplex edit that makes us multivirus resistant. These are things where you think it might be germline, but it might be just as feasible or at least feasible enough. Maybe it'll be more expensive, less equitably distributed. Nice thing about germline is every subsequent generation gets it for free. So, some people say that's a bug or a feature depending how you look at it.
But if you can do it, it will get cheaper to do it somatically. And it will be inherited in the way that we used to be an inheritance, which is what your great grandfather hands down to the great-grandchildren, a set of technologies, tools, possessions. That multiplex editing will be something that won't be germline, but it will be just as surely inherited.
Dr. Patrick: Right. The equality of access is interesting as you've brought up multiple times because, you know, like HIV is great because, I mean, HIV is essentially cured with the right drugs. And most developing...people live in developed countries with, you know, healthcare can do that. That's not the case for, you know, developing nations with governments that aren't, you know, running correctly. And so it's an interesting point that, you know, is it easier to genetically cure HIV through the germline or, you know, eliminate poverty essentially when you're talking about something? I mean, potentially, I guess.
Dr. Church: Yeah. I think eliminate poverty sounds like a moonshot, but I think it qualifies as a positive grand challenge more like the satellites than the moonshot. And it may not be so far off in that there could be a virtuous positive feedback loop where you reduce the medical load from infectious disease and other diseases that slow down, not just the individual who has a disease, but the whole family, whole village around that person because they want to...they care for that person. And then that lightening of the medical load results in a little more time and money to dedicate to things like educating children, adult women, and so forth. And then that results in better medical care, and it just gets better and better. It could help.
The other thing that could help is, you know, better agriculture, maybe less use of land and water for animals and more on nutritious plants. Golden rice is an example of something where vitamin A deficiency kills a million people a year, and golden rice is one cost-effective way of reducing the poverty burden, you know, to town with a few blind people that are likely to go...be dead within a year or two of going blind. But anyway. I think that the diseases of poverty can be eliminated in that manner.
We also could in principle... HIV is one of the infectious diseases that is mostly human-specific, even though a lot of these so-called human-specific diseases did come from an animal originally. I mean, where else did it come from? But it's so rare that if you eliminated it, it would be essentially extinct like smallpox. I mean, there could be another pox virus that replaces smallpox someday, but the point is smallpox has been eliminated for so many decades that is unquestionably a success. And I think the same thing could be done with HIV.
Condoms is another thing that works a little bit better in the industrialized nations. It doesn't really necessarily protect against uncooperative partners or rape, that sort of thing. So, I think we need... This is a multi-pronged effort to eliminate HIV, but once we do it, it could be like smallpox.
It's been recalcitrant of vaccines, which are so powerful. The latest round of vaccines are kind of in a format of gene therapy and are very inexpensive compared to most gene therapies that are typically $2 million. In the case of COVID-19, there was as little as $2 for adenoviral caps that are around the double-stranded DNA for three of the top five vaccines.
Dr. Patrick: You talked a little bit about genetic counseling, and, you know, there's next-generation embryo selection. I'm interested in your thoughts in the practical and/or philosophical differences between, you know, doing next-generation embryo selection and germline editing. I guess, to put it another way, you know, does advances in sequencing and understanding of the genetics of disease and complex traits, polygenic traits, eventually lead to a point of practical editing through embryo selection?
Dr. Church: I think it will be intermediate. It won't be as powerful as one could do with germline genome engineering, but it could achieve many of the same goals for, you know, eliminating certain diseases. Many of those diseases that could be eliminated by in vitro fertilization-embryo choice could also be eliminated or greatly reduced by preconception choices if that were more common. It's really a matter of social norms. So, there's a tiny sector of society that practices preconception decision-making, and those have almost eliminated major serious genetic diseases. Why it isn't common in other parts of society is a complicated socio-economic educational cultural issue.
But I think there will be a tipping point where people realize...you know, get to know their own genome better, get to know their choices when they're still very young and dating. And there's a whole variety of ways it could work out so that things are done before the point of in-vitro fertilization, which is not...it's not the most pleasant medical procedure. I mean, the hormone treatments have negative consequences for quite a few women. Sometimes it has to be repeated multiple times, sometimes six times, in case of one of my colleagues was the result of six rounds of IVF.
But the number of embryos that could be made by in vitro fertilization could skyrocket without in any way interfering with the germline and so forth by epigenetically reprogramming cells to become pluripotent stem cells. And then the pluripotent stem cells can become eggs, and then those eggs, they might be randomly mutated. And if you sequence enough of them, you'll find one that is what you want.
So if you haven't induced the mutation with CRISPR, it just happened the way it happens in the world. This is far from efficient compared to editing. It illustrates how we have this kind of double standard that if you do it...if you achieve the same goal, germline engineering, this way, it's okay, this way it's not okay. It's same as GMO argument. If you mutate, you know, a tomato or soybean by random ultraviolet mutation, where you're making hundreds of mutations random with no control, that's somehow more attractive than if you do a precise edit, and you make sure the rest of the genome is clean and you haven't touched anything else. You know, for some people, that makes sense, for other people, it doesn't. It's like saying that, "Oh, if I'm going to, you know, fix my car engine, I'm going to, you know, throw all kinds of random chemicals and shotguns and stuff into it and hope that one of those things makes the right fix to the car." But anyway.
What's going on in germline is very similar to what's going on in GMOs. You can radically change the plant species by one method but not by another. You can change an embryo's fate but, you know, negatively with chemotherapy or positively by IVF but not by germline editing. It's doublethink. Yeah. It's good topic of conversation, and eventually, I think it will sort itself out.
Dr. Patrick: What about understanding the unknown? So, there's a lot of genetic variants that are thought to be mostly deleterious or, you know, "not beneficial." But upon deeper inspection perhaps there's an advantage and a scenario we don't quite understand. I've read some articles. You kind of talked a little bit about this, not necessarily in the regard of, you know, germline editing or anything, but with respect to the importance of neurodivergence, you know, and how you have narcolepsy and how you've basically...I think you talked about, you know, many creative ideas coming from potentially having that "disorder." So I'm kind of just curious on your thoughts about how to foresee or like what...you know, like that sort of territory, understanding the unknown, you know.
Dr. Church: Right. So it's very similar to other technologies. It was unknown, well, the cell phones were going to fry our brains. It was unknown, you know, for MRIs, which have, you know, very big magnets. You know, locomotives crashed. They collided head-to-head because of poor scheduling. So there will be negative consequences. Some of them are caught in the phase one, two, and three clinical trials that FDA requires. Some of them are caught later, sometimes semi-humorously referred to as phase four clinical trials, meaning that's out in the population and catch them later. Like hormone replacement therapy and Vioxx are two examples...recent examples. Thalidomide is a slightly older example.
So, I think the point is not to have zero risk. There is no way to have zero risk. Doing nothing is very risky. Status quo is very risky relative to the future. So what we need to do is just be very cautious. Start with small animal studies or human organoids. Start with small human clinical trials, and then slowly grow as we gain confidence, it is safe and effective.
In the specific examples where there's a trade-off. I mean, I think it's very interesting to talk about trade-offs. Sometimes people will say, "What about the perfect human?" I said, "Is there a perfect human?" I mean, what does that even mean? Is there a perfect means of transportation, is a comeback? You know, it's like, is a bicycle perfect or is it the supertanker? You know, bicycle is not so good at carrying, you know, tons of goods, and supertanker does not get you to school in a few minutes.
So, there's no perfect. There's all these trade-offs that depend on the environment. So, people will say, "Well, CCR5 is not a good idea for germline." And maybe it's not even a good idea for somatic because it could make you sensitive to West Nile or to certain influenza. But another way of thinking about it. Well, you don't have to knock out CCR5 just because there are people walking around with CCR5 nulls. You could be more nuanced where you take out the parts so that you engineer the protein as we were talking about earlier with the machine learning. You knock out the parts of the protein that binds to the virus but not the parts of the protein that do their immunological function. So you could end up with something that's HIV resistant and West Nile resistant rather than or...
And, you know, I think narcolepsy and dyslexia that I've had, and ADD, OCD, high-functioning autistic, bipolar, these do have potential advantages to society. We don't have to eliminate them, but we should maybe give the affected people a choice if we can. It's not always but some of the damage is done during embryogenesis. But some of that might be fixable as an adult, or we might be able to give them a knob that they can twist, they could say, "Okay, I want to be autistic for the next three days so I can get...you know, finish my thesis." You know, I can just focus and just don't think about human relations, and then I can dial it back because I have to meet with the president of the university, you know, and I have to be charming and not, by his definition, his neurotypical view of the world. And so you're accommodating, or, you know, you name it.
A lot of the reason that neuroatypicals are beneficial is not because that particular disease is not a disease or that particular disease benefit. It's just because we're off of center in any direction, maybe even obesity or religious choice. Anything that takes us far away from the center of the bell curve makes us feel alienated, which gives us maybe more time to pursue intellectual activities rather than social media or it makes us focus on like proving that we're just as good as the handsome, you know, well-articulated, you know, model in the middle of bell curve.
So anyway, whatever it is, it isn't necessarily a particular thing that we need to preserve in the population, although we should think creatively about that. Dr. Patrick: So maybe one last topic before we end, and another area of the research that you've been involved in is the gene drive. Maybe some people listening or, you know, watching know what that is but using it to eradicate insect-carrying human disease like malaria.
Dr. Church: Lyme disease. Yeah.
Dr. Patrick: Yeah, Lyme disease. Yeah. So I'm just, sort of, curious about, you know, your work on that and your work on also trying to make sure you address concerns like unintentionally leading to extinction of the species or something.
Dr. Church: Right. So, I think one approach to... So the extinction of species is one part of it. You see, you can do gene drives whose intention is to make a species resistant to something that's bad for a third species. So, for example, you could make mosquitoes resistant to malaria. They don't carry it onto humans, so there's a three-species problem. And you're not really making anything extinct necessarily, although since malaria is a human-specific disease, you might make malaria extinct. But you could inadvertently, I think the scenario you're painting here, inadvertently make that mosquito extinct as well.
Now, there's a limited number of mosquitoes that carry malaria, maybe half dozen major ones out of 3,500 species of mosquito. One could argue that there are very few known species that are dependent upon mosquitoes. The males are pollinators. Females are the bloodsuckers in this case. But even mosquito fish do not depend on mosquitoes. But anyway, we should do more study of the ecosystem interactions. We should test them extensively to see that they don't cause extinction. They have these large enclosed ecosystems, you know, that includes small villages and farms and so forth.
Extinction tends to occur more easily in small populations as long as the environment is still complex. So we could do tests like that. But it also helps if the species that we're putting at risk is okay to go extinct. I mean, there are a lot of species going extinct, than I probably, you know, getting rid of half a dozen mosquito species that...where we're pretty confident that they don't impact other species might be acceptable. But first priority is to try to do it without that.
And the way that it's going to make it, again, into public positive consciousness is...you know, my former postdoc and colleague at MIT, Kevin Esvelt, has gone to Nantucket and Martha's Vineyard and asked whether they would be favor having a gene drive wipe out Lyme disease, they hate Lyme disease, but the gene drive wipe out Lyme disease, do nothing or to have a non-gene drive shock-and-awe whole new engineered rodent population that is resistant to Lyme disease but not via gene drive.
And of those three scenarios, I think they like the third one the best. They don't want to do nothing. They don't want a gene drive just yet. Let's try a genetically engineered rodent population, so a little more expensive, a little...you know, probably less sure. That's the kind of communication, the dialogue between almost all the people on the islands or their representatives in the town councils. They were surprisingly interested in the science and how it could affect their Lyme disease, a horrible disease.
It'd be hard to do the same thing in malaria. That's why Lyme might be a better choice for these two different GMO strategies. But I think that's the pathway by which it might get better. There is a pretty good Lyme vaccine that was blocked for no particularly great reason. It happened to bad timing that happened around the same time as the fake data on vaccines causing autism. Wakefield, I think was the scientist name who faked the data later was...when that was revealed. But the damage was already done. People kept repeating it as a core fact for many years after it was shown to be false. And so they pulled the Lyme disease vaccine off.
Now, back then Lyme disease was also less serious disease. I think that if they were put to a vote today, they would have kept the vaccine. And there are some new vaccines that are slightly better aimed either at multiple tick-borne diseases, not just Lyme, multiple strains of Lyme. Hopefully, those will...since now people do know the consequences of voting against the vaccine, hopefully, they'll accept it this time. It's been in use in dogs the whole time. It's one of these cases where dogs get better medical care than humans do because, you know, we love our dogs, and apparently, we don't care about ourselves.
Dr. Patrick: Yeah, your experiments with the dogs and seeking FDA approval for that being a treatment in animals is pretty exciting.
Dr. Church: Yeah, as is the Lyme disease vaccine for dogs.
Dr. Patrick: Okay. So I have a personal question for you. You know, we talked a little bit about the narcolepsy. And I know I've read that you've attributed a lot of creative ideas to perhaps being in a limbo between dreaming and awakeness. But I'm wondering, like, you know, what your day is like, you know, and, like, do you have, like, a routine? How do you get these, you know, creative ideas or, you know, remember them or just kind of any insights into that?
Dr. Church: Yeah. I mean, first of all, any personal stories that the scientist says shouldn't be taken as like recommendations, but they're just anecdotes. The recommendations come from clinical trials. It's a little hard to do with things, you know, like narcolepsy, but it's possible. Anyway, in my case, you know, I found...first of all, I found that I had it. You know, it's one of these diseases that you...could be very impactful, but nevertheless, combination of ignorance and denial and so forth. I just didn't recognize it until I was maybe late 30s, probably had a serious onset when I was 13, looking back on it. I had a lot of headaches, took a lot of medications for headaches. The headaches disappeared but sleepiness started kicking in much more.
So after discovering it, one thing I do is I communicate it. I don't hide it. Sometimes your diseases that you don't tell people about can kill you more than the things that you communicate. So, you know, narcolepsy is potentially fatal in, you know, traffic accidents. I know some of my colleagues hid their diabetes from everybody except me, which could be fatal, almost was fatal in one case, just because the people around him didn't know what was happening when he went into shock. So that's one thing is disclosure. You know, I'm not necessarily recommending that. I'm just saying what I do.
The second thing is I don't eat during most of the day. I eat right before I go to bed, which is not a good thing for most people. You want to eat well before you go to bed. Basically, the tendency to go to sleep after a meal, which is true for many people, is especially true for me, and so I found that that was good. If I'm not in a conversation like this...I tend not to fall asleep in conversations, but I will fall asleep in lectures, so I tend to try to stand or pace or do some other activity that's not too...doesn't require too much brain power, but it keeps me awake. I will, however, fall asleep standing up or walking or even riding my bicycle. And I don't drive, so that's...it's another coping mechanism. There's a whole bunch of jobs that I couldn't get. I'm unemployable in many jobs. So I happened to pick one that fits okay. Those are some anecdotes.
I think you want like for inspiration. You know, I don't have a lot of control over it. I tend to fall asleep when I'm either super bored or super excited/have a difficult problem. So I have a difficult problem, very, very commonly, I'll fall asleep. If my computer is having trouble or crashing, I'll fall asleep. And I'll often come up with an answer to either the abstract problem or the practical problem within seconds of waking. I wake up like. Some people are kind of groggy. I'm like already at like heightened state of awareness when I wake up from a nap. The naps lasts anywhere from a second to an hour usually in the multi-second range. Anyway, it's a very strange experience. I'm not sure I recommend it, but you get used to it after a while.
And as you're going out, your decision-making is very poor. You're like blurring reality with the dream world. You're incorporating things that you're seeing because your eyes are still open. Typically, my eyes are still open, and then I'll be completely asleep. When I didn't know that I had it, I would... I did have a driver's license for a few years. I would pull up to a stop light, and I'd put on the parking brake because I didn't know I was going to go to sleep, but didn't want to go to sleep without the parking brake. At that point, I sort of, realized I got a problem. I went to sleep clinics to make sure that I had a problem. Then I stopped driving.
Dr. Patrick: I don't know how much of this is true. I once read that Salvador Dali used to put a spoon on his nose, and he'd sit up and fall asleep with it. When he would wake, you know, the spoon woke him or something when it was falling, that he had this inspiration and creative ideas for his paintings. And I don't know if it's real.
Dr. Church: I think that is true, and I think it's true for a lot of people. He just tried to capture it. He tried to, you know, harness it. There's one set of theories that dreaming is where you're doing kind of trash collection and you're, like, cleaning up house or preparing yourself for unlikely scenarios. And you really shouldn't interrupt that. It's not good for you. But if your goal is to harness weird stuff, then it's a good thing. So, yeah, his art is...it really reflects the dream state, I think, better than most of the Dadaist and surrealist artists around that era. So maybe he had something. You know, it's hard to say. He was good at making up stories, though. Yeah, definitely.
Dr. Patrick: Well, Dr. Church, thank you again, such an honor to have you on the podcast and have a discussion with you, be able to ask you some questions. I usually, at the end of the podcast, direct people that want to kind of follow more of your work. I know you're on Twitter. Your Twitter handle is @geochurch, G-E-O-C-H-U-R-C-H. You also have a lab website, and if you google Church Lab website, it's like the first hit. But you also wrote a book, published was in 2014, "Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves." And there was a very kind of interesting backstory to that.
Dr. Church: Well, there are a bunch of back stories to that one. Let's see, which one are you thinking about?
Dr. Patrick: I mean, you know, whichever is the most interesting.
Dr. Church: I'll tell two. Well, the short one is Ed Regis was a co-author, and my agents and publisher wanted me to have a ghostwriter. And I did not feel comfortable with having a true ghostwriter where you don't acknowledge them. So, Ed had just interviewed me for "Discover Magazine," and he had written, I don't know, nine popular science books already. So I thought that would be a good partnership, and I learned a ton about writing. I hope you enjoyed his lessons in synthetic biology. That was one part.
The other thing that's probably slightly more interesting is the book was encoded into DNA, and I bet that's what you were thinking. I got to the point where...we've been working on reading and writing DNA for a few years, and I realized, "Hey, we can read and write very easily. Why don't we write a book in DNA and then read it" with the best technologies of the day. And that was partly prompted by a review that I wrote of a scientific paper where the authors had synthesized a very tiny genome and had put their names into the genome in a simple code. And I was asked to review that paper, Craig Venter, Clyde Hutchinson, Ham Smith for some of the senior authors.
And so I reviewed the article, and I decided I would write it in DNA, the whole review in DNA. And I sent it then in a different code than they had used. I thought it was a better code. And the editor normally you would think would send it back to me and say, "Look, use English." But instead, the editor sent it on to them, you know, unchanged without any English at all.
And fortunately, one of the senior authors, I think was Clyde Hutchison, knew enough programming that he broke the code and wrote through...and understood the review. So, then having written that code to write the review, I said, well, I'll use that same code to do my book because it was already available. The code had the advantage. Theirs only dealt with uppercase letters, while mine handled zeros and ones.
Zeros and ones were a much more general encoding method, and so that could not just encode the uppercase letters, but pictures. Pictures in JPEG form are zeros and ones. You know, in principle later, movies, audio, all kinds of things have been encoded using the zeros and one strategy.
I did the book, made my 70 billion copies, which is more than, you know, like the top 100 books put together prior to that. To my surprise, it kind of launched an industry. There's now an international consortium for this kind of digital encoding. It's not displacing, you know, disk drives, but it's moving in that direction.
But another thing that's happening is we're incorporating it into recording into living organisms, which I kind of alluded to when we're getting...you know, why would we do a million edits is we can record physiological data. So, for example, we've recorded two terabytes of information in a mouse in one billionth the mass of the mouse. So it's one of the world's smallest recording devices. A billionth of a mouse can encode two terabytes. And the next step will be to take it up to 20 petabytes using these multiplex or repetitive elements.
So those are two of the backstories. There's a few more. Some of them are documented in the book. I'll let the readers read the books. I think the book really has not aged much since 2014, even though the field is like exponentially improving and so forth, the book, I think, was futuristic enough that it wasn't wrong yet. Anyway.
Dr. Patrick: Well, I look forward to reading it. I learned a tremendous amount just from doing some background research. I had no idea, synthetic biology. I knew so little about it, and, you know, I came into this podcast. I've focused a lot on aging and I'm very...what humans not interested in...what human adult is not interested in aging, right?
But after preparing and doing this background research and reading this field of synthetic biology and just everything that you're doing is just so exciting. I mean, just an understatement, just so exciting. So thank you so much for all your research and, you know, what you're going to continue to do. I mean, the world, you know, you're going to be history books and all that stuff. So again, a huge honor. Dr. Church, thank you so much.
Dr. Church: Oh, thank you. You've created one of the best set of questions I've ever seen. You took us from where most people stop to a whole another level. And I hope the next interview starts where you left off if possible. But anyway, terrific job, and I greatly enjoyed it. So, it's hard to believe you didn't know much synthetic biology before this, zero.
Dr. Patrick: But I'm reading your book. I'm so excited. I can't wait to continue...
Dr. Church: I'm writing another one now. It's been eight years. I have a lot of day jobs, so I don't have that much time. But it won't be exactly a sequel, but it'll be wildly different. I learned a lot from writing that one. This one I'll probably write solo or I have been writing solo so far. So, anyway.
Dr. Patrick: Well, I hope to have another conversation with you again. Thank you.
Dr. Church: Okay. Sounds good. Take care.
Dr. Patrick: You too. Thanks.
A protein involved in the aging process in many mammals, including mice and humans. Alpha-klotho is the receptor for fibroblast growth factor-23, which regulates phosphate homeostasis and vitamin D metabolism. Serum levels of alpha-klotho decrease after the age of 40 years, a phenomenon associated with several aging-related diseases, including cancer, hypertension, and kidney disease.[1]
One of three common genetic variants of the APOE (apolipoprotein E) gene. The APOE4 allele, which is present in approximately 10-15% of people, increases the risk of developing Alzheimer's disease and lowers the age of onset. Having one copy of E4 increases risk 2- to 3-fold, while having two copies increases risk as much as 15-fold.
A developmental disorder characterized by impaired social interaction, behavioral problems, and poor communication. Autism typically manifests in early childhood and is slightly more common among boys than girls. In clinical trials, sulforaphane, a compound derived from broccoli and broccoli sprouts, reduces the characteristic behaviors associated with autism.
Two nitrogen-containing molecules (called nucleotides) that form the "rungs" of the ladder-like structure of DNA. The DNA in a single chromosome contains approximately 150 million base pairs. The number of base pairs within the telomere region of chromosomes are of particular relevance to the field of aging. The length of telomeres, distinct structures comprised of short, repetitive sequences of DNA located on the ends of chromosomes, ranges from 8,000 base pairs in a newborn to 3,000 base pairs in an adult and as low as 1,500 in elderly people. The average cell loses 30 to 200 base pairs from the ends of its telomeres each time it divides, contributing to (and serving as a marker of) aging.
A form of viral resistance to HIV that arises when a person has genetic patterns that inhibit the expression of CCR5, a protein found on the surface of certain immune system cells, including CD4 T lymphocytes. Also known as cysteine-cysteine chemokine receptor 5, CCR5 acts as a coreceptor (a second receptor binding site) for HIV when the virus enters a host cell. CCR5 plays roles in longevity and immunity to other viruses, so gene editing strategies that target CCR5 as a means to induce HIV resistance may inadvertently shorten lifespan or increase vulnerability to certain viral infections.[1] [2]
A characteristic of the genetic code in which more than one codon can encode for a single amino acid. Degeneracy arises because there are more codons than encodable amino acids, with 64 possible codons pairing to only 20 amino acids. Evidence suggests that codon degeneracy makes DNA more tolerant to point mutations.[1]
A genome editing technology. CRISPR (short for clustered regularly interspaced short palindromic repeats) exploits naturally occurring gene editing processes used by bacteria. It targets specific stretches of genetic code and edits the DNA at precise locations, using the cell's own DNA repair machinery to add or delete pieces of genetic material. CRISPR can also be used to make changes to the DNA by replacing an existing segment with a customized DNA sequence. CRISPR may be beneficial in treating a wide range of genetic disorders, cancer, and other health conditions.[1]
A gene-editing technology that employs a prokaryotic enzyme called Cas9 and an RNA guide molecule to home in on its target DNA. Cas9 then edits the DNA to disrupt genes or insert desired sequences. Cas9 makes up part of a prokaryotic immune system, which confers resistance to foreign genetic elements such as plasmids and phages.
A genome editing technology that combines cytosine or adenosine deaminases (enzymes) with CRISPR-Cas9. Cytosine or adenine deaminase base-editing facilitates direct, irreversible conversion of a specific DNA base into another at a specific gene target without introducing double-strand DNA breaks.[1]
Multiple cytotoxic effects of gene editing have been identified, including DNA-related damage (such as the introduction of double-strand breaks), cyclic GMP-AMP synthase activation (resulting in autoimmune activation), off-target mutagenesis, and the disruption and/or activation of endogenous genes.[1] [2]
A double-stranded molecule that carries the genetic material for an organism. Each strand of DNA is composed of nucleotides strung together by covalent bonds. Nucleotides are typically identified by the first letter of their base names: adenine (A), cytosine (C), guanine (G), and thymine (T). They form specific pairs (A with T, and G with C) via hydrogen bonds, which in turn provide the helical structure of the DNA strand. Specific sequences of the nucleotides comprise genes.
DNA is packaged around histone proteins in units referred to as nucleosomes. Each nucleosome contains 147 base pairs of DNA. Complexes of DNA, RNA, and histone proteins comprise chromatin. Chromatin’s primary function is to compress the DNA into a compact structure that can fit within the nucleus. Chromatin structure and DNA accessibility can be altered by epigenetic modifications, or “tags,” such as DNA methylation and histone modification. Epigenetic changes, which do not alter the overall sequence of DNA, are heritable and can regulate patterns of gene expression.
Cytotoxic lesions on DNA in which both strands of the DNA are severed. Double-strand breaks arise from exposure to exogenous agents, such as radiation and certain chemicals, as well as through endogenous processes, such as DNA replication and repair. Gene editing techniques often induce double-strand breaks. Although these breaks can be repaired, the repairs are often imprecise.[1]
Genetic control elicited by factors other than modification of the genetic code found in the sequence of DNA. Epigenetic changes determine which genes are being expressed, which in turn may influence disease risk. Some epigenetic changes are heritable.
A hormone produced primarily in the liver that plays important roles in energy homeostasis and metabolism. FGF21 acts via a paracrine effect, a form of cell-cell signaling. Evidence suggests that FGF21 delays thymic involution, thereby serving as a pro-longevity hormone.[1]
The process in which information stored in DNA is converted into instructions for making proteins or other molecules. Gene expression is highly regulated. It allows a cell to respond to factors in its environment and involves two processes: transcription and translation. Gene expression can be turned on or off, or it can simply be increased or decreased.
A plant, animal, or microbe whose DNA has been altered using genetic engineering techniques that favor the expression of desired physiological traits. Although GMOs are found widely in agricultural, industrial, and pharmaceutical settings, they are the subjects of considerable controversy.[1]
An organism whose codons have been reassigned to create an alternate genetic code, with the goal of improving cellular properties. Genetic recoding enhances genomic flexibility, potentially introducing novel functions and capabilities into an organism.[1]
A genetically modified form of rice that has been engineered to produce beta-carotene (a vitamin A precursor) in its endosperm. Golden Rice was designed to combat vitamin A deficiency in the developing world.[1] Its creation is an example of biofortification, the process by which foods are genetically modified to increase their nutritional value.
Haploid cells contain only one set of chromosomes. Reproductive cells (ova and sperm) are haploid. Diploid cells contain two sets of chromosomes (one from each parent cell). Somatic (non-reproductive) cells are diploid.
The result of the physical exchange of identical DNA regions on two separate chromosomes or on the same chromosome. Homologous recombination is critical for the repair of DNA double-strand breaks and facilitates chromosome repair and other aspects of chromosome maintenance. As such, it plays key roles in maintaining the integrity of the genome. [1]
Having identical alleles for a particular genetic trait. Homozygosity occurs when an individual inherits the same alleles for a particular gene from both parents. If the gene is associated with a particular disease, carrying both alleles can markedly increase an individual’s risk of developing that disease.
A condition characterized by abnormally high blood cholesterol concentrations. Hypercholesterolemia is associated with increased risk for cardiovascular disease, particularly coronary artery disease. Treatments for hypercholesterolemia center on dietary and pharmaceutical interventions, such as low-fat diets and statins, respectively.
An enzyme that facilitates the insertion of viral DNA into host DNA. Integrases are found in retroviruses, such as human immunodeficiency virus. They have been exploited as useful tools in genome editing.[1]
Vitamins and minerals that are required by organisms throughout life in small quantities to orchestrate a range of physiological functions. The term micronutrients encompasses vitamins, minerals, essential amino acids, essential fatty acids.
The use of gene editing techniques to target and alter multiple DNA loci within a genome with simultaneous precision. Multiplex editing is faster and more efficient than earlier gene-editing techniques.[1]
An insulating sheath composed of protein and fats that surrounds nerves. Myelin facilitates neural transmission by promoting rapid impulse conduction along axons. It is produced by the Schwann cells in the peripheral nervous system and by the oligodendrocytes in the central nervous system. Demyelinating diseases, such as multiple sclerosis, damage myelin, slowing nerve impulses and eliciting a wide range of neurological complications.[1]
A condition characterized by an extreme tendency to fall asleep whenever in relaxing surroundings.
Three-dimensional tissue cultures produced from stem cells. Organoids mimic the structure and activity of the organ from which they are derived and are useful tools in many areas of biomedical research.
A laboratory procedure in which the circulatory systems of two distinct organisms are surgically joined, creating a single, shared physiological system. Parabiosis facilitates the study of normal physiology as well as pathological states, such as obesity, diabetes, and the aging process. Studies using heterochronic parabiosis (the joining of organisms of dissimilar ages) have demonstrated that the blood of a young animal has restorative effects on its conjoined, older partner, rejuvenating tissues of the nervous system, skeletal muscle, heart, liver, and other organs.[1]
An enzyme that participates in cholesterol metabolism by binding to and degrading the receptor for low-density lipoprotein (LDL) cholesterol, thereby influencing blood cholesterol concentrations. People who carry mutations in the PCSK9 gene variant are predisposed to familial hypercholesterolemia (elevated blood cholesterol) due to enhanced PCSK9 activity. PCSK9 inhibitor drugs utilize antibodies that target and bind free plasma PCSK9, promoting its destruction. The PCSK9 gene is a candidate target for gene editing.[1]
A quality of stem cells, characterized by the capacity to differentiate into any type of cell. Pluripotent stem cell technologies form the basis of regenerative medicine, with applications for neurodegenerative disease, neurological trauma, cardiovascular disease, and pancreatic dysfunction.[1]
Capable of developing into any type of cell or tissue except those that form a placenta or embryo.
DNA that has been manipulated and "recombined" to produce sequences not otherwise present in the native genome. Recombinant DNA has been utilized for advances in cancer research, reproductive medicine, vaccine production, diabetes treatment, agriculture, and other areas.
A type of virus that uses RNA (instead of DNA) as its genomic material. Once inside a cell, retroviruses use an enzyme called reverse transcriptase to convert their RNA to DNA. The viral DNA then integrates itself into the host cell's DNA, thereby coopting the cell's transcriptional machinery and allowing the retrovirus to replicate. The human immunodeficiency virus (HIV) is a type of retrovirus. HIV is currently under investigation as a target for gene editing therapy.[1]
A molecule that participates in the flow of genetic information from DNA into proteins.
A complex molecular machine that participates in protein synthesis via the process of translation. The ribosome translates codons (three-nucleotide combinations) found on the messenger RNA template and matches them with their respective amino acids. Each newly translated amino acid is added to the growing protein chain until the protein is fully synthesized.
Senescence is a response to stress in which damaged cells suspend normal growth and metabolism. While senescence is vital for embryonic development, wound healing, and cancer immunity, accumulation of senescent cells causes increases inflammation and participates in the phenotype of aging.
Proteins that initiate homologous recombination by annealing (reconnecting) complementary DNA strands that have been separated via heating. The use of SSAPs for the repair of double-strand breaks (which may arise naturally or in the process of gene editing) often results in the loss of genetic information.[1]
A highly contagious disease caused by the variola virus. Smallpox first emerged in humans approximately 3,000 years ago and is widely considered one of the deadliest diseases of all time. In 1980, public health authorities announced that smallpox had been eradicated, the first human infectious disease to be successfully eradicated worldwide. Smallpox is still a concern, however, because of the potential for its use as a weapon of bioterrorism.
Any type of cell that comprises an organism’s body. Somatic cells do not include gametes (sperm or egg), germ cells (cells that go on to become gametes), or stem cells.
Somatic gene therapy involves the introduction of genetic material into somatic (non-reproductive) cells, with the goal of expressing therapeutic gene products. The new genetic material cannot be passed on to a subsequent generation.[1] A gene therapy affecting the germline, on the other hand, involves genetic modifications that impact the germ (reproductive) cells (sperm or ova). This genetic modification would be passed on to subsequent generations.[2]
A multidisciplinary field of science that involves the redesign of existing biological systems and the design and engineering of new systems. Synthetic biology relies on gene editing and gene writing technologies and has applications in industry, agriculture, and medicine.[1]
A drug widely used in the 1950s to prevent nausea and morning sickness in pregnant women. Thalidomide caused severe birth defects in approximately 10,000 children worldwide and was eventually banned. However, its use has reemerged in recent decades to treat certain types of cancer and skin diseases, including Hansen's disease. The thalidomide tragedy led to the adoption of rigorous, pre-marketing testing of pharmaceutical products for developmental toxicity.[1]
Enzymes that facilitate the movement of transposable elements (called transposons) in DNA. Transposases and their counterparts, recombinases, are one of four classes of CRISPR/Cas-derived genome editing agents used for modifying genomes in experimental settings.[1]
A DNA sequence that can move from one location on the genome to another. Sometimes referred to as "jumping genes," transposons can create or reverse mutations, causing alterations to the cell's genetic identity. Transposition often duplicates the genetic material.
Infectious diseases that can be transmitted from animals to humans (or the converse). Zoonotic diseases arise from a variety of pathogens, such as bacteria, viruses, parasites, and others. They account for nearly two-thirds of all infectious diseases in humans and include anthrax, salmonellosis, tuberculosis, Lyme disease, AIDS, Ebola virus disease, and ringworm, among others.[1]
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