Human gene editing: 'There is tremendous promise for this powerful technology'

Human gene editing allows scientists to delete, repair or replace bits of cell DNA in a biological form of cut and paste. Harvard Medical School Professor George Daley says this could one day help treat acute conditions.

In a landmark decision on Monday, Britain's Human Fertilisation and Embryology Authority gave researchers approval to conduct gene editing experiments on human embryos.

Scientists will not be creating babies, with the modified embryos destroyed after seven days. The goal, researchers say of the work, is to better understand human development in a bid to improve fertility treatments and prevent miscarriages. DW spoke with Harvard Medical School professor and director of the Stem Cell Transplantation Program at Boston Children's Hospital, George Daley, following the announcement.

DW: Professor Daley, what are scientists hoping to achieve with the gene editing research which was given the go-ahead on Monday in the UK?

Professor Daley: Gene editing is a very powerful technique which allows us to manipulate genes, knock them out, alter their sequences. And by doing that in the early human embryo, you can reveal lots of important information about how embryos develop. We typically study embryonic development in animal models - mice, cows, pigs and the like - but we know that the human embryo is very distinctive, it's different and the principles that we've learned in the mouse and other mammals do not apply in humans. So, this is very important work.

There is no denying gene editing is rather controversial; do the potential benefits of what we can learn from this research outweigh the fears that some people have?

I believe so. The controversial aspects of this work really pertain to changing genes in babies, in the context of in vitro fertilization (IVF). What has been approved in the UK is purely laboratory-based, fundamental inquiries about the nature of early human embryo development.

This is incredibly important work, it's going to teach us about infertility, the basis of miscarriage and the understanding of the earlier stages of human development and it's also going to teach us about birth defects. The work is fundamentally important, and I think we can distinguish work that stays in the laboratory from the thornier issue of using this technology to change traits in human individuals. That's something that I, as a member of a large group of scientists, have called for restraint - merely to allow us to understand the safety issues involved, but even more importantly to participate in a public debate so that we can achieve societal consensus about what, if any, might be permissible uses, versus those we want to restrict.

George Daley

Professor Daley says rigorous oversight of such technology needs to be in place

If we move away from designer babies, and focus on people who are already alive - can such gene editing research be used to cure existing illnesses?

There is tremendous promise for using this very powerful technology of gene editing in somatic tissue, body tissues - not involving babies and birthing through IVF, and not involving the germ-line.

For instance, in various blood diseases, like sickle cell anemia - that's a very devastating, painful condition of abnormal red blood cells - there is a strategy where you can use this technique to alter a single, very small part of the blood-cell genes and it would essentially, at least we predict, alleviate the devastating consequences of sickle cell anemia.

There are other applications that scientists are envisioning, rendering blood cells resistant to HIV, treating cells in the retina for reversing blindness - the opportunities are really vast in human medicine.

How will this kind of technology assist HIV/AIDS research?

The most specific application has to do with a very fascinating observation made a number of years ago, that certain individuals that carry a particular gene variant in a receptor for the virus, that is sort of the docking site on the cell for the virus, these patients are resistant to HIV. Now, they seem to be healthy in virtually every other manner and the strategy for using gene editing would be to clip this receptor, to delete this receptor protein in the healthy cells and make them resistant to infection by the virus.

This is a strategy that may be able to be used therapeutically and in individuals who are already infected - that's being tested. But, more importantly, it may in fact be able to be used as a quasi vaccine approach to prevent HIV. There are really some very exciting possibilities for treating and preventing HIV using this technology.

Menschliche Embryo-Zellen unter dem Mikroskop

Critics of the practice argue that researchers are messing with the genetic make-up of embryos

Some people say gene editing is messing up the genetic make-up of embryos. What can scientists do to convince people of its benefits?

Well, scientists first of all have to do the hard work. They really have to do the painstaking research that would prove in fact that we can - with great precision and reasonable safety - actually alter genes, ideally genes involving human disease and really prove the value.

I think that will be first done clinically in somatic tissues, perhaps in the context of a bone marrow transplant or a gene therapy for blood disease and then in the longer term it's not really up to the scientists to decide how it is used - if it is ever to be used in changing actual human traits, changing traits in the germline.

That is a decision that would have to engage a much, much broader range of stakeholders and that's a process that I don't think we are anywhere near, we are just starting to think about that process.

Has Monday's announcement in the UK to allow gene editing for research purposes set a precedent amongst the scientific community?

Any time you get an approval, through what is certainly a very rigorous process of scientific oversight, it does serve as a message. It would embolden other scientists to say, we could, with similarly-warranted research, obtain approvals and move the field forward.

I am participating in the updating of the International Society of Stem Cell Research guidelines. We are planning to issue these formal guidelines in March. These guidelines will provide the kind of oversight process that would allow this type of research to go forward - it is rigorous oversight, it involves both peer scientific review, as well as ethical and societal review.

Our hope is that across the globe, scientists consider this type of research - it's important research, so we hope many scientists will - that they do it in a highly responsible manner, inviting oversight, inviting the type of external scrutiny that would give the public the confidence that the work that is being done is highly justified.

Is it going to take a Nobel Prize for human gene editing for it to become mainstream and acceptable?

It's already mainstream. Everyone anticipates that this technology will be awarded a Nobel Prize. But it's going to be difficult to figure out the many people who have made major contributions because the Nobel can only award to three. But, this technology has already been absorbed into most major molecular biology labs across the world. It is such a powerful technique, so easily applied, that it has really just taken the scientific community by storm.

That means it's going to find its way into cancer research, infectious disease research and there are many other applications outside of biomedicine - you may have already heard that there are strategies for altering plants to make them resistant to disease, strategies for altering mosquitoes so they can no longer be a vector for malaria or the Zika virus. The impacts for biomedicine are great, but the impacts for global agriculture and the ecosystem are also both promising and challenging and require very, very thoughtful review before they're launched.

George Daley is a professor at Harvard Medical School and the director of the Stem Cell Transplantation Program at Boston Children's Hospital. Daley is a past president of the International Society for Stem Cell Research.

This interview was conducted by Jessie Wingard.