Archive for the ‘Genetic Modification’ Category


First genetically enhanced human babies? Maybe

Tuesday, 27 November, 2018

A researcher in China claims to have used CRISPR to perform gene-editing on human embryos, two of which have been brought to term. If true (a big if), this would likely be the first case of germline genetic engineering (of nuclear DNA at least). But without any peer-reviewed publication, all we have are the unverified claims of a researcher. Even with peer-reviewed publications, this could still be a case of fraud and would require additional verification. So there’s a reason to be very skeptical.

As repercussions for this, the researcher has been suspended from his university, giving a statement that the experiment did not have ethical approval.

So what was the first gene to be edited? Apparently it was a deletion of the C-C motif chemokine receptor 5 (CCR5). This receptor is a protein on the surface of white blood cells, which the human immunodeficiency virus (HIV) uses to infect the immune system. A small percentage of people naturally have 32 DNA base pairs deleted from the CCR5 gene (this mutations is called CCR5Δ32), which renders them immune to (most) HIV infections and also some poxviruses (like smallpox). However, this only protects against the the R5 strains of HIV,  whereas the X4 strains can use another pathway (via CXCR4) to get into white blood cells. There have been documented cases of people with the CCRΔ32 mutation being infected with HIV, so it’s not total immunity to HIV.

This modification is not without side-effects either, as it may increase susceptibility to fatal influenza infections. In addition, only one of the two children had both copies of CCR5 (allegedly) deleted, whereas the other only one copy was deleted.

This is a sensible choice for a first genetic engineering target in one sense, in that it’s an easy modification to do (a deletion) and it’s something that already exists naturally so we know what the effects will be. It’s a perfect low-hanging fruit for genetic enhancement in this sense, but it’s still not a particularly beneficial target for genetic engineering because HIV is essentially a completely treatable infection in most developed nations. The reports suggest that at least one of the parents of these children had well-managed HIV, giving a further justification for this particular choice. However, if the father was the one with HIV, there are already ways to avoid transmission though IVF.

Given the risks of a new technology like CRISPR, a target should not only be one that is feasible to do and where potential side-effects are known, but also a target that is not already treatable with other technologies.

In addition, it’s not totally clear that this is a form of gene therapy or genetic enhancement. We traditionally think of vaccines to prevent diseases as a part of therapy (as we do anything that prevents, alleviates or cures a medical condition), and this is essentially a genetic version of a vaccine against HIV so likely isn’t an example of enhancement. But the line is pretty blurry anyway, and it’s possible deletion of CCR5 may improve cognitive function. So it may well be that the first case of germline genetic engineering of nuclear DNA in humans was a case of enhancement.


Two Australian ethicists on gene editing of human embryos

Wednesday, 27 September, 2017

An article was published today in The Conversation titled “UK gene editing breakthrough could land an Aussie in jail for 15 years: here’s why our laws need to catch up“. It was authored by two Australian ethicists, Christopher Gyngell and Julian Savulescu. who argue that gene editing for research purposes should be legal. The key argument is as follows

Many are worried about the long-term implications of such gene editing research, and claim it sets us on a path to “designer” babies. But in the UK where the Nikian study was performed, the laws make a distinction between the research and reproductive applications of gene editing.

Under the UK’s regulatory regime all reproductive applications of gene editing are banned. Such a distinction is also made in Australian laws between the use of cloning for reproductive purposes (which is prohibited) and cloning for research (which is permitted). Making a distinction between reproductive applications and research enables clearly beneficial research to proceed while preventing controversial applications.

I think this makes perfect sense. Many of the arguments used to justify a ban on gene editing of human embryos do not apply when those embryos are never implanted in a womb (and those that do apply to research on genetically-engineered embryos already apply to current research on non-edited embryos). So this distinction between reproduction and research is a sensible one to advocate.

There is, however, a telling implication in one section:

But such research is, at the very least, premature. Most experts agree gene editing science is far too immature for us to be thinking about reproductive applications in humans. But the technique can today be fruitfully used to study development, as the Niakan study shows.

The implication is that one day reproductive applications will be possible. And both authors have been on record advocating for gene editing of human embryos for reproductive purposes:

Germline Gene Editing (GGE) has enormous potential both as a research tool and a therapeutic intervention. While other types of gene editing are relatively uncontroversial, GGE has been strongly resisted. In this article, we analyse the ethical arguments for and against pursuing GGE by allowing and funding its development. We argue there is a strong case for pursuing GGE for the prevention of disease. We then examine objections that have been raised against pursuing GGE and argue that these fail. We conclude that the moral case in favour of pursuing GGE is stronger than the case against. This suggests that pursuing GGE is morally permissible and indeed morally desirable.

I happen to totally agree with these authors on both research and reproductive use of genetic engineering, but I know that people who oppose the reproductive use of genetic engineering will argue against this using a slippery slope argument. And given the two ethicists arguing for the meaningfulness of the distinction between reproductive and research uses of genetic engineering advocate for both sides of that distinction, it will be hard to refute that argument.


No, gene editing won’t ruin human evolution

Friday, 13 January, 2017

An article published in TIME magazine by Jim Kozubek, titled “How Gene Editing Could Ruin Human Evolution” basically argues that it’s too risky to edit our genes. I’d agree with most of these risks, but none of these risks are insurmountable and none of them are good arguments for preventing gene editing entirely.

Genes are complicated, but not impossibly complicated

It is definitely true that most traits are controlled by many genes, and that many genes control many traits. As Kozubek says:

Biology is robust against breakdown. It straddles risk like a money manager, and that straddling of risk over the entire genome is one reason there are so few single “targets” for many of these psychological and cognitive traits. Indeed, many of these genetic variants may be pleiotropic, meaning they have different, often unrelated effects in different cells or tissues

This does certainly complicate any potential gene editing, as many areas of the genome would need to be edited and these might have unintended consequences. But this added complexity is still solvable. If gene editing technology is good enough, there’s no reason we can’t edit half a dozen areas of the genome instead of just one.

Furthermore, if one gene does have different effects in different tissues, that just increases the complexity of the genetic engineering problem but still doesn’t make it impossible. With somatic genetic engineering, one could target the genetic edit to just one organ (like the brain), without it effecting that gene in the rest of the body. One could also potentially duplicate the gene entirely and edit only one copy, plus adjust the regulatory sequences so that the edited gene is the only one expressed in the tissue of interest and the unedited gene is the one expressed in other tissues.

Gene editing isn’t about what is right, but what is right for each individual

Kozubek seems to to come very close to saying that scientists don’t understand evolution and that genetic diseases don’t exist, when he says:

Second, scientists tend to think of men as machines, genes as their broken parts and variations in life as problems to be solved—aberrations outside the normal curve. This assumes there is a right way for genes to be. In reality, Darwin showed us that evolution does not progress toward an ideal model or a more perfect form, but instead is a work of tinkering toward adaptation in local niches. Nowhere in nature does it say how a gene should function.

Genes have a fitness, which refers to how successfully those genes allow the organism to reproduce in a particular environment. But we, as humans, also can place value judgement on certain phenotypes (traits an organism possess) that may or may not correlate with fitness. For instance, a genetic disease that causes an increased chance of an early death decreases fitness and is something most humans don’t want. But sometimes a gene might increase your fitness, perhaps by making you super fertile, but you as a human still don’t like that trait. And some traits we might want, like to be able to eat as much we want without getting fat, may decrease our fitness in some environments where food is scarce or increase when food is plentiful. Basically, there’s not really a correlation between what evolution is aiming for and what we humans are aiming for.

The argument that scientists are trying to restore genes to their natural, correct or ‘healthy’ state is a fundamental misunderstanding of what most proponents of genetic engineering want. We want to be able to give people the freedom to choose what genes they, or their children, have. Indeed, this is one fundamental issue with the notion that we should only use genetic engineering to make people healthy but not do anything like enhancement: there isn’t universal agreement on what healthy is. What many of us might think as natural or ‘healthy, such as being able to hear, might be considered by some as an unwanted disability.

Diversity does not trump autonomy

Similar to the first argument, Kozubek argues that certain things thought of as diseases or disabilities can offer advantages in fitness in certain contexts.

Furthermore, genetic variants that predispose us to risk or supposed weaknesses are precisely the same ones that turn out to have small fitness advantages (they make us better at numbers, more sensitive, alter concentration…). This is one reason I am a “neurodiversity advocate.” Evolution works at the margins, and it does so through trade-offs: Often, you don’t get an advantage without risking a disadvantage. This is not trivial.

It is undoubtedly true that all advantages come with disadvantages, just as all drugs come with side-effects. As I alluded to above, a gene that increases risk of obesity in modern society might offer a significant advantage in a food-scarce environment. A genetic enhancement that allows humans to see in ultraviolet light might require allowing so much UV light into the eye that it increases the risk of macular degeneration. An enhancement that increases wound healing by preventing scar formation might increase the risk of infection.

One key point to this, however, is that these are all environmentally dependent. Our environment now is very different to what it was when we did most of our evolving, as we now have a lot more food, the ability to produce sunglasses to block UV light and enough antiseptics and antibiotics to prevent infections when they occur. I simply don’t see how somebody could argue that the mutation in the CFTR gene, which causes cystic fibrosis if you have two copies but resistance to tuberculosis if you have one copy, is a worthwhile trade-off in Western nations where tuberculosis is very rare.

The other key point point is that people should be informed of the risks and benefits and allowed to make their own choices for gene editing (within a broad ethical framework, of course), just as we do with pharmaceutical treatments. For example, some might see an increased risk of autism as a fair cost for greater mathematical ability, whereas others may not. Even if having a diverse set of genes in the population benefits the species somehow, I certainly don’t think we can use this to justify forcing people to keep, or pass on to their children, the genes they have. Are you really going to cite the need for genetic diversity in human evolution as a reason to deny a patient a gene therapy they desperately desire? Are you going to make somebody deaf in the hope they become a genius composer like Beethoven?

Evolution will continue

The final point, relating to the  later points, is that genetic engineering will break evolution:

And genetic risk variants remain in the population because they’re advantageous to certain people, given the right genetic background or conditions. Those risk variants are speculating—evolution, always and forever, takes chances.

The problem with this is that it assumes that gene editing will somehow decrease the genetic diversity in the population.  As I briefly mentioned a while back in response to an SMBC comic, there is no reason to think this would be true. Yes, we’re likely to get rid of many of the genetic diseases that we can, because most people see those as bad things. But there are many traits where there is little consensus over which is better, and may companies may have different techniques to produce these traits, so diversity of these genes may increase.

We’re also likely to transfer genes from across the natural world (like fluorescent proteins from jellyfish) or create entirely new genes. This process of adding and editing our genome is vastly faster than waiting for mutations, so there will be ample variation in the population.

Human evolution will definitely be different, but it will still continue. But that’s no different to any other treatment or technological intervention that changes how often we pass on our genes. Whenever humans treat the sick or help our injured, we’re altering the progress of evolution. But this doesn’t make medicine or technology bad. In fact, these things are probably pretty good, even if they change evolution. And so, even if it changes our human evolution, I think gene editing will be pretty good too.


Is germline genetic enhancement better than somatic genetic enhancement?

Monday, 25 July, 2016


The various types of human genetic modifications can be divided along two lines – the therapy-enhancement divide and the somatic-germline divide. The former refers to whether a modification is therapeutic or enhances and the latter refers to whether a modification is affects children (by affecting reproductive cells or whole embryos) or just affects the body (without affecting reproductive cells).

We are therefore left with four categories (Resnik 2000):

1. Somatic gene therapy (SGT)
2. Germline gene therapy (GLGT)
3. Somatic genetic enhancement (SGE)
4. Germline genetic enhancement (GLGE)

What I want to explore is whether, in a world where adults can opt to be genetically enhanced, there would ever be any benefit to germline genetic enhancement. That is, can we avoid all the ethical issues with germline engineering and genetically enhance only consenting adults?

I think there are three general reasons why it might be beneficial to genetically modify the germline, rather than waiting until people are old enough to consent. (However, note that some of these benefits might be achieved by somatic engineering in infancy, which would essentially create a ‘designer baby’ while leaving the germline untouched. This wouldn’t side-step any ethical issues around consent so I’m ignoring this possibility)

1. GLGE could be in the child’s best interests

The vast majority of enhancements people would seek in adulthood would also be things people would want their children to have as they grow up. It is likely also that children themselves would choose (if they were legally able to consent) to go through school with improved intelligence, to play with better reflexes or to be physically attractive while experiencing the first teenage romance. And that’s not mentioning things like resistance to disease or faster wound healing that exist on the cusp of the therapy-enhancement divide.

2. GLGE may be technically superior to SGE

Some modifications may be technically difficult to achieve in an already developed body consisting of billions of cells, and may prove much easier when only single celled gamete or zygote is modified. It might be difficult to get the DNA to every cell that needs to be modified, and some modifications might, at least initially, only prove possible if the genes are edited before the body’s organs and systems develop.

However, it’s quite possible that an enhancement which was only possible with germline methods would 18 years later could be achieved – or even surpassed – by somatic methods. In this case, if you imagine persons could give consent at age 18 for somatic gene enhancement, then any advantages of GLGE over SGE would only be temporary ones during childhood and at the age of consent everyone would be on an equal playing field again.

A fast pace of biotechnological progress would also mean that inherited germline enhancements might be little benefit to future generations compared to somatic enhancements that exist by that time. If a mobile phone could survive over generations, you’d still not pass it down to your children because it would be hopelessly outdated. So barring major disasters that set humanity back into a dystopia with little technology, passing your enhancements on to your children would only be a benefit if germline enhancements remain far superior to somatic enhancements over that time.

3. GLGE can affect motivations

Though a person choosing a somatic enhancement will choose based on their wants, the effects of a germline enhancement can directly affect what it is that a person will want (once they are old enough to choose). To paraphrase German philosopher Arthur Schopenhauer: “Man can choose to do what he wants but he cannot choose what it is that he wills”. I should point out that genes cannot control everything, but they can have some affect on the future choices a person will make.

This means that narrow-focus enhancements which are desired by only a few, or even undesirable to anyone who could choose, may be only be possible by way of modifying the germline (or somatic modifications in children). Portrayals of germline enhancement in science fiction often involve armies of soldiers or slaves engineered from conception or childhood to not only excel at their designated role but also to enjoy being perfectly obedient. These portrayals often involve growth rate enhancements to get around the reality that such such soldiers or slaves would take decades to ‘manufacture’. In practice, anyone with the power, resources and decades worth of time to commission and care for their own soldiers or slaves would either be ethically prepared to use somatic techniques to modify the desires of adults or be otherwise be able to pay/bribe adults to do the same job.

Because people sometimes make choices they regret or that aren’t in their best interests, there may be benefits to altering a person’s motivations. It may be reasonable to desire that your children make ethically good and smart choices once they become adults. So, if any germline enhancements can improve logical reasoning and moral motivations, children gifted with such enhancements will be in a better place to make wise choices, including when selecting which somatic enhancements they pursue as adults.


I think there are some very good practical reasons to pursue genetic enhancement of the germline and of children. There may still be ethical reasons to oppose it, but I think the potential gains are large enough some at least will feel it ethically acceptable (or ethically right) to pursue germline genetic enhancement even in a world where somatic genetic enhancement was possible. If parents are pursuing enhancements out of love, they may be prepared to do ethically questionable things to achieve what they believe is best for their children.


Superhuman reflexes

Tuesday, 24 May, 2016


Though perhaps best exampled by Neo in the 1999 film The Matrix, superhuman reflexes to some extent are an attribute of so many superheroes that it’s basically a default superpower. But just how realistic would it be for us to expect genetic enhancement to enable people to have such quick reflexes? That’s what I’m going to attempt to answer in this post.

First we need to define some terms. Biologically, a reflex is a simple and automatic response to a stimulus. If you touch something painfully hot you will automatically withdraw your hand, so it’s a reflex. You can still learn or unlearn a reflex, but the important thing is that a reflex is done without thinking: your brain isn’t really involved. If, out of the corner of your eye, you see something falling off a table and quickly grab it, that’s not a reflex. You don’t automatically grab any falling object, and if that object was a knife you’d leap away from the table rather than try to grab it, which is a sure sign your brain is processing the situation rather than it being automatic.

As you’re probably aware, there is a delay between the stimulus (e.g. touching something painful) and the response (e.g. pulling your hand away) of a reflex. The main factor determining this delay is how fast the signal can travel along the nerve cells (neurons) from the hand, to the spinal cord, and back down to the muscles (there’s a slight delay as the signals cross the synapse from one neuron to another, but its contribution is minor). In humans, the neuronal conduction velocity varies between different nerves, but let’s just look at the ones sending the signal from the hand to the spinal cord (which travel at about 50 meters per second) and those that send signals from the spinal cord down to the muscles (which travel at about 100 meters per second). So travelling a meter along your arm and then another meter back means the fastest possible reflex would occur after 30ms (it’s a bit slower than this in reality, but let’s go with this).

So the question now turns to how we can get neurons to conduct signals faster. There are three tactics that animals use to do this. The first is making the neurons thicker in diameter, which is why the neurons that control our muscles are the some of the thickest in our body at up to 20 micrometers. But some animals, like squid, have neurons that are are 500 micrometers, but our neurons are still 4 times faster. This is because animals like humans have a second strategy, which is to insulate the neurons with a substance called myelin. This allows the neurons to be much smaller while still being really fast, which is essential for packing as many brain cells as possible into a small skull. But the record for the fastest neuronal conductional velocity in the animal kingdom belongs to a penaeid shrimp, which not only has fairly big neurons (at 120 microns) and myelin insulation but also has a third mechanism where in between the neuron and the insulation is a gap filled with super conductive salty fluid that further speeds up how fast the signals can travel (for a discussion of these mechanisms, see Castelfranco & Hartline 2016). Their neurons can send signal at 200 meters per second, twice the speed of our fasted human neurons.

Given that we need to fit our nerves through the holes our vertebrae (the neural foramina), we can’t really rely on increasing the size of our neurons. And we’re already fairly well insulated. Maybe we could use some shortcuts like the penaeid shrimp do, but without the increase in size it’s unlikely we’d get to the velocities of 200 meters per second the shrimp achieve. Any genetic enhancement to human reflexes is realistically going to be much more modest.

But let’s say we do manage to double the speed of our neurons, what would that be like? Well, a simple doubling of conduction speed would more or less halve our reaction time. Our reflexes would be faster, but so too would the speed at which we could think and perceive things. Our sense of time wouldn’t change, but given the limitations of our current neurons the closest we can come to seeing what the world would look like with double speed neurons is watching a video at half speed (which you can easily do on YouTube). This would give a massive advantage in martial arts and many sports like sprinting, fencing, tennis, football and baseball.

But would this magnitude of reflex enhancement be enough to dodge a bullet? Almost certainly not, and not least because we have only speed up the nerves while leaving the muscles as slow as ever. The simplest test of visual reaction time of the sort you’d need to dodge a bullet is the ruler drop test, where you try to catch a measuring stick as quickly as you can after noticing it has been dropped. This therefore captures both the ability to visually detect movement and perform a simple movement (a pinch grip) in response. The average reaction time, on this test, for athletes is about 200ms. Even if your reaction time has been enhanced to be half that of a normal man, a Glock 17 has a muzzle velocity of 375m/s so in the 100ms it takes you to react by moving your muscles the bullet would have traveled 37.5 meters. The gunman would have to be quite a distance away to allow you to duck behind cover as soon as you see the gunshot. And the bullet would still be traveling too fast for you to see, because we only enhanced reflexes not your visual perception speed (which would involve making photoreceptors in the retina work more rapidly), so you would still be attempting to dodge a bullet that you cannot actually see.

So genetic enhancement of reflexes has many practical limitations in comparison to the fanciful portrayals we see in fiction, but would still be immensely advantageous in competitive sport or hand-to-hand combat where every millisecond matters.

In order to get extremely rapid reflexes, we’d need to do away with the limits of biological systems altogether and transmit signals through electronic circuits, which could a million times faster. When it comes to quick reaction times, robots or perhaps cyborgs will have a massive advantage. At the moment robots already have faster “reflexes” than humans, but the human brain still outperforms artificial intelligence if the stimulus requires complicated visual or spatial processing or if performing a novel movement requiring coordination. But maybe one day, robots won’t only be beating us at chess but also fencing, tennis, baseball and martial arts. And by then, maybe we’ll be able to implant that technology into our own body, and truly gain reflexes faster than anything the biological world can offer.


UK approves experimental genetic engineering of human embryos

Saturday, 6 February, 2016

Good news from the United Kingdom, with the UK Human Fertilisation and Embryology Authority (HFEA) being the world’s first regulatory authority to explicitly approve genetic engineering of human embryos. There are other countries who haven’t banned the technology, but this is the first one to purposefully allow it.

Of course, these won’t be designer babies, as the experiment must cease after the embryos are about 256 cells (about two weeks old). But this is necessary to study the effects of the technology so that maybe one day it will actually be safe enough to use for therapeutic or reproductive purposes. See more about the story in Nature News, Wired and The Guardian.

You can also read some opposition to the decision, with Craig Venter writing in Time and Donna Dickenson in The Telegraph. Both pretty much argue that we don’t yet know enough and should be cautious, and with this I agree. But unless we take the few cautious steps forward by doing the research, we’ll never know enough to be able to edit human genomes. Somehow I think that’s precisely the outcome the opponents want.


Mitochondria transplants at risk of rejection

Tuesday, 1 October, 2013

Those mitochondrial transplants (or ‘three parent IVF’ as it is innaccurately called at times) that I’ve blogged about before (here, here and here) might have a few side effects on gene expression. Replacing mitochondria affected by a genetic disease with those from a gene free donor has been compared to replacing faulty batteries in a camera with fresh new ones. But a recent policy opinion piece published in Science (Reinhardt et al 2013) suggest this analogy might not be totally accurate. One of the authors, Edward Morrow, is quoted in New Scientist:

“For a modern camera you’ve not only got to have the right brand of battery, but the right size, shape and voltage. There are all these parameters you have to have right. You can’t just go into a shop and buy any old one.”

As explained in the piece in Science, the mitochondria of some organisms like fruit flies, mice and monkeys has been shown to interact with the genes being expressed in the nucleus, and thus it probably does the same in humans. Non-invasive methods of replacing mitochondria have been used in most of these studies, which involves mating a male mouse of one line with a female mouse of another line, to produce mice with the mitochondrial DNA of line 2. These offspring were then only crossed to line 1, which after a few generations produces mice that mostly have nuclear DNA of line 1 but the mitochondrial DNA (mtDNA) of line 2 (this is sort of similar to if your mother’s mother’s mother was from a totally different ethnicity to the rest of your family). The results of these experiments were that mice with a ‘mismatch’ had reduced exercise capacity (Nagao et al 1998) and reduced learning ability (Roubertoux et al 2003).

Thus, it’s at least theoretically possible these ‘rejection’ side effects might exist in humans too. We just don’t know, it’s a different species and a different method of mitochondria replacement to those studies. This therapy has been tentatively approved by the Human Fertilisation & Embryology Authority in the UK, and the UK government is drafting regulation for the use of this therapy. This paper shouldn’t change that, as any new treatment is likely to have side effects. The question is whether it’s worth it. I agree with how the Science piece concludes:

Assessing the costs and benefits of MR [mitochondrial replacement] treatment requires that prospective patients are as fully informed as possible. The difference across patients in the severity of expected offspring symptoms in the event that MR treatment is not taken will shape the decision of choosing the treatment versus waiting for the outcomes of further research. Some families who are predicted to be, or who have previously conceived offspring that were, severely afflicted by mtDNA diseases are more likely to be prepared to take the risk. Others whose children are expected to suffer less detrimental symptoms, cognition problems or infertility, may wish to wait for further empirical clarification of the risks involved.

This treatment is very promising for severe mitochondrial diseases. For milder conditions, it might not be worth the risk until we know how the mitochondria and the nucleus interact, and can better work out what mitochondria a good donor needs to have for any given patient.



Some words of wisdom

Tuesday, 24 January, 2012

I’ve written about mitochondrial transplants for human embryos before (especially how it isn’t new, having been first done in 1998), but it still is getting a lot of press as a “three-parent IVF” method. But fortunately the Wellcome Trust has an article to set them all straight on the science of it. I like this part:

1 + 1 + 0.00001 ≠ 3

Also, in an article to The Times the Wellcome Trust’s director, Sir Mark Walport, wrote this very pithy sentence:

 If a child with donated mitochondria can be said to have three parents, then the recipient of a heart transplant could be said to have four.

Damn straight!


There’s no gene for stopping bullets.

Wednesday, 24 August, 2011

There’s been a bit of talk recently about the bio-artist who managed to create a fabric of human skin and spider silk that managed to stop a .22 calibre round. Unfortunately the bullet didn’t ricochet off the skin, Superman-style. This skin acts a bit like a net stopping a soccer ball, in that it simply catches the bullet. Now imagine you kick the ball with superhuman strength into the net of soccer goal. If the net can’t stop the ball, one or both of two things will happen: either the net will break leaving a hole where the ball went through or the net will just tear right off the goalposts and both net and ball will keep sailing by.

In the case of this bulletproof skin/fabric, the skin wasn’t broken by the bullet. Instead, the bullet (now wrapped in spider silk and skin) still penetrated a couple of inches into the ballistics gel behind it.

For a visual, watch the video below (specifically the frame at 7:48).

Note that a Petri-dish sized piece of fabric was attached (through indeterminate means) to the ballistics gel. So as the bullet hits the middle of this circle of fabric, it pulls taut and in the case of the spider silk fabric, pulls off completely and envelopes the bullet. To go back to the soccer goal analogy, you can have a really strong net but if it’s poorly attached to the goalposts, it won’t stop a really fast ball. So while it’s possible that the tensile strength of the spider silk is enough that, if the fastening held, the bullet would be stopped completely, it is also possible that the skin would have broken had the fastening not broken first. More tests are needed, of course.

But anyway, if that gel was your heart, you’d still be very dead. So despite claims that the skin was ‘bulletproof’, the skin didn’t even stop a .22 bullet travelling at reduced speed. To be classified as a Type I vest (the lowest class of ballistic vest), the skin would have to completely stop a full velocity .22 round.

So, it’s not even bulletproof. And, it is just spider silk fabric covered in skin, it’s not really skin either. And so of course the press reports that bulletproof skin has been created and we transhumanists can rejoice at the promise of invulnerability.

That bastion of great reporting, The Daily Mail, quotes Dutch bio-artist Jalila Essaidi as saying:

“Now, let’s take this one step further, why bother with a vest: imagine replacing keratin, the protein responsible for the toughness of the human skin, with this spidersilk protein. This is possible by adding the silk producing genes of a spider to the gnome[sic] of a human: creating a bulletproof human. Science-fiction? Maybe, but we can get a feeling of what this transhumanistic idea would be like by letting a bulletproof matrix of spidersilk merge with an in vitro human skin.”

Yes, they said gnome. I lolled. But anyway, why would we bother with a vest? I don’t know, the fact that it actually works might be one reason. Or that it can be much tougher without having to also be nice and supple enough to allow you to move like skin does. And we can trade up to the newer models without having to have a new skin transplant or more genetic modification. The only disadvantage of a vest is not being bulletproof all the time.

Still, it’s kind of cool to have bio-artists out in the world experimenting with weird and wacky ideas like bulletproof skin, while all the ‘real’ doctors and scientists are trying to find ways to heal people with severe burns or gunshot wounds. Then again, it doesn’t mean much if the research is poorly tested and demonstrated on YouTube instead of at a scientific conference.

So will it ever be possible to have bulletproof skin? Probably not.

You see, our skin is flexible and can stretch pretty easily. If it didn’t stretch, we’d to moult and grow a new skin as we grow, get pregnant or gain weight. Also, we’d find movement difficult too (as anyone who has tried to squat in a pair of skin-tight jeans knows). Skin has to be this flexible even if we make it strong enough to stop a bullet. So despite a bullet not actually penetrating the skin, the skin will rapidly deform allowing the impact to cause severe underlying trauma, fracture bones or injure vital organs. (This happens with any soft body armour, and is called ‘behind armour blunt trauma’ or BABT). So although stronger, bulletproof skin might prevent penetrating injuries (and yes, save lives), bullets will still be potentially lethal. Bullet resistant skin? Possible. Nigh invulnerability thanks to bulletproof skin? Highly unlikely.

Or at least, it won’t look like skin. An hard exoskeleton like a crab, perhaps. But if we’re going for exoskeletons, I think Iron Man’s looks like a better option.

(And I know I totally glossed over the part where the spider silk was produced from the milk of a transgenic goat, but that’s because it’s 11-year-old news.)


Targeted gene therapy for HIV/AIDS

Saturday, 5 March, 2011

Some scientists (I still have no idea who) reported treating six patients with ex vivo gene therapy for the treatment of HIV/AIDS. Researchers used zinc finger nucleases to edit out the CCR5 gene from CD4-positive T-cells. Because HIV (or, most strains of it) uses the CCR5 protein to infect CD4+ T-cells, this essentially creates white blood cells that are immune to HIV. People with a deletion in their CCR5 gene (5-14% of Europeans have at least one such deletion, the CCR5-Δ32 allele) are essentially immune to AIDS (though they can sometimes get asymptomatic HIV infections).

All six patients showed some immune recovery, with five showing up to 6% of their cells modified, so that’s progress, I guess. Side effects were just a couple days of flu-like symptoms. In this study, the cells were removed from the patient and edited outside the body, probably because the ridiculous safety standards required for gene therapy that I recently blogged about pretty much rule out modifying the patient’s genes directly (i.e. in vivo). And I suppose the zinc finger nucleases probably aren’t as efficient as using a virus, so it wouldn’t really work in vivo just yet.

This is, however, the first time that human gene therapy has actually deleted a gene, rather than adding one. Pretty soon, addition, deletion, modification, replacement…it’ll all be possible.

Some scientists are, I think sensibly (with just 6% of cells modified), trying to avoid the work being overhyped as a ‘cure’. For example, Dr Michael Kolber, professor of medicine at the University of Miami:

“[This study] was a proof-of-principle that they could go in and do this. They demonstrated that the [genetically engineered] cells stayed in the patients, but the patients were not cured”

Of course this gets reported as:

Experts are reacting with cautious optimism…but they say the jury is out on whether the technique might ever spell an end to AIDS.

No, the jury isn’t out on whether the technique might ever work, just whether it has worked. It’s obvious beyond a reasonable doubt that gene therapy could provide both immunity and cures for HIV infections. And I’d say it’s obvious that gene therapy could cure all disease (and I’m not overhyping, just don’t expect these cures tomorrow and without side-effects during their early stages of development).