Home / Others / In the midst of a tumult, a Chinese scientist defends the creation of genetically modified babies

In the midst of a tumult, a Chinese scientist defends the creation of genetically modified babies



HNGO KONG – The scientist who has made #crisprbabies a news story on Twitter this week has defended his experience by creating the world 's first genetically modified babies and the bold way in which he has them. had announced – through the press and a YouTube video – Wednesday International Summit on the editing of the human genome.

"For this particular case," said He Jiankui about the twin girls born out of his job, "I'm proud." And far from admitting a second thought about what other scientists have termed "frightful gesture that threat of in the field of editing the therapeutic genome, "he dubbed: he stated that he had started another pregnancy, still at an early stage, with genetically modified embryos .

He began with more humility in his first public remarks about his research., with a statement that drew the attention of the audience: "I have to excuse the fact that these results were leaked before peer review," he said. declared.

publicity

In fact, his representatives had contacted a reporter a few months ago and had allowed many shootings in his lab to tell the story of his work, as he had acknowledged.

He meticulously orchestrated the announcement Sunday, two days before the start of the summit, of his claim that girls, created from genetically modified embryos, were born a few weeks earlier. He has interviewed the Associated Press, who was the first to report on the news, and published a series of online videos in English, instead of publishing his research in a scientific journal. And when he submitted his slides to the summit organizers before the conference, they did not include anything about the work that had already led to births.

He also admitted that his university was unaware of what he was doing.

A number of eminent scientists have not been persuaded by He's comments. "I do not think it's a transparent process," said David Baltimore of the California Institute of Technology and chairman of the summit's organizing committee during a lengthy question-and-answer session. responses following his 20-minute presentation. "We only learned that … after the birth of the children. I think the scientific community has failed to self-regulate because of lack of transparency. "

When asked why he had hidden his work from the scientific community, he claimed that he had not done it. He said he had made a presentation at Cold Spring Harbor in the United States in 2017 and had spoken with a scientist at the University of California at Berkeley and ethicists in the United States. It was only with the Berkeley scientist that he revealed his plan to create baby genes..

He also revealed that he had now submitted the study to a newspaper, while stating that he would not communicate the full results to the scientific community for review before publication of the document.

The news of births has caused an uproar among scientists here and western, as it has crossed a line of conduct agreed by leading scientific organizations around the world against altering the genome of embryos for the purpose of reproduction. Such a modification of the germ line results in any modification of the DNA being inherited by future generations. Genome editing technology is also relatively new and poses technical and safety issues, including the risk that DNA is inadvertently cut off the wrong place.

After being excused for the "escape", he embarked on the defense of his work with discreet insurance. People living with HIV / AIDS suffer overwhelming discrimination, he said, and a significant number of children are infected. This led him to choose as a CRISPR target a gene called CCR5 which, once deactivated, produces a cell receptor so crippled that HIV can no longer use it as a portal in cells. People who have mutated the CCR5 genes are therefore protected against HIV infection.

His answers have not always been convincing, reminding some scientists of the evasiveness of politicians during Sunday morning TV debates. When David Liu of Harvard University, one of the leading developers of genome editing tools, blamed him for pursuing an experiment that did not address an "unmet medical need" (HIV can be avoided and treated), he stated that the work was justified because the HIV-positive father of the twins felt that this technique allowed him to have children who would be forever immunized against HIV. He also stated that he had "personal experience" with HIV, knowing that some villages had an infection rate of 30%.

He Jiankui speaks at the International Summit on the Human Genome Publishing in Hong Kong on Wednesday. Kin Cheung / AP

"It's even more horrible and heinous now," said STAT Liu, co-founder of the Beam Therapeutics genome publishing company. "His answers revealed a deeply troubling naivety about the issues involved. I have a deep fear that this could delay the ground [of therapeutic genome editing] so bad that patients will not get the treatments they desperately need. "

Other public experts were also critical. "After listening to Dr. He, I can only conclude that this was wrong, premature, useless and largely useless," said Bioethicist Alta Charo of the University of Wisconsin, a member of the committee. Summit organization.

Most of his presentation described the techniques he used and the discoveries he made in experiments with mice and monkeys, such as the discovery that genome editing was most effective when was made near fertilization; He therefore administered the CRISPR-Cas9 genome editing molecule by microinjection with the sperm used to fertilize an egg. But "multiple" injections of CRISPR were needed to increase the efficiency of editing to ensure that most cells contained the DNA edition.

He is an expert in DNA sequencing, a technique he used to determine if CRISPR caused unintended genetic changes. He discovered an untargeted modification to an embryo before implantation, he said, but felt that it would probably not affect any biological function. When parents found the problem acceptable, "the couple chose to implant this embryo to start a pregnancy on two embryos," he said. He added that the sequencing done after the births did not confirm the off-target modification.

Another problem was that only some of the cells of the early embryo had been successfully modified; others have retained their original CCR5 gene, which means that they might actually not be protected against HIV. Again, he said that the parents had accepted this "mosaicism" and that they wanted the embryo to be implanted. Finally, one edition resulted in the absence of five amino acids in a CCR5 protein. It is unclear if this is serious enough to disable the receptor and prevent HIV infection, Liu said.

This cavalier attitude has also enraged his critics. Harvard's Liu, who said he had to take an antacid tablet during the conversation to not be sick, said that it was "abominable" to expect that parents, who probably have little or no scientific training, make a decision like this, apparently without any help.

Most questions focused on the process of obtaining informed consent from parents who volunteered for the trial. He admitted to obtaining the couple's consent himself rather than having it done by an untrained and trained professional.

"I explained to each family, line by line and paragraph by paragraph" the meaning of the informed consent form, said He, who was criticized for telling patients that the experiment involved a " AIDS vaccine ". In addition, the form indicates the participants agree to protect "the trade secrets of the project team".

"Patients received a consent form that falsely stated that it was an AIDS vaccine trial and confused research and treatment by saying they were" likely to benefit, "Charo told STAT. .


Eight couples enrolled in the study and one dropped out, he said. In each case, the father was HIV-positive and the mother was not. A total of 31 embryos were injected, he said, and 70% were published.

The turmoil around his work, he said in response to a question, has caused the pause in the clinical trial of using CRISPR to disable CCR5 in human embryos, due to the current situation. very early.

He added that the twins, named Lulu and Nana, are in good health and that there is a plan to monitor the children over the next 18 years, in the hope that they will consent as adults to surveillance and surveillance. ongoing support.

The conversation was eagerly awaited because he, 34, had not provided any evidence to support the claims of AP's story. It would not reveal where the twins were born or where their family lived. He told AP that he had sought ethics approval from a board of the Harmonicare Hospital for Women and Children in Shenzhen, but that he was not one of four who provided embryos for research. having led to births. Since then, the hospital said that the girls were not born there either.

Participants, several dozens of scientists and journalists, had formed a waiting line in front of the glass doors of the auditorium of 500 people at 7:30 am – three hours before the start of the session – but the room had about 60 empty places. Just before its session, however, three security guards with well-known earphones took up a position near the front of the room and a crowd of photographers and journalists rushed in, filling the aisles and searching for the latest seats available. (and seemingly bored in a final way during the four interviews, before it is).

"I am fully aware that this session is attracting some interest," said moderator Robin Lovell-Badge, development biologist at the Francis Crick Institute in London, at the opening of the session, that nearly 5 000 people watched via the webcast.

"We have to give him a chance to explain what he did and why," said Lovell-Badge, adding that "we will close the session immediately" if there is "unruly behavior" when his speech.

Unlike other speakers, sitting in the front row and summoned to the stage when it was their turn to speak, he entered through a side door, walking briskly to the podium under polite applause.

Earlier this week, Harmonicare announced that it was investigating all links it had with Dr. He's research and condemned the use of genome editing in IVF embryos used to establish a pregnancy. The National Health Commission of China has asked officials in Guangdong Province, where the Shenzhen laboratory is located, to investigate its research, but it is unclear what laws or guidelines it may have violated in China , where regulations on genome editing and human embryo research are more flexible than those in many other countries, particularly the United States

And the University of Science and Technology of Southern China, where he has his lab but is on leave since the beginning of the year, issued a statement in which he said he knew nothing about the research he had done, claiming that it "seriously violated ethics and academic standards." . "

An editorial of the China Daily said that an experience like this "could be disastrous if conducted without stringent security safeguards," saying such research is "considered a no-no." The newspaper adds, "We do not know why he did this experiment, it would be to his shame if he did it just to become famous, so a thorough investigation is more than necessary and urgent."

He graduated from the Hefei University of Science and Technology in eastern Anhui Province and earned his Ph.D. He worked as a postdoctoral researcher in Stephen Quake's Stanford University lab, and then returned to China in 2012 to join Southern University, then this year, in the technology-rich southern city of Shenzhen.

Even though his criticisms continued on the sidelines of the meeting as well as during some formal talks, there was a sense that the assembly of human embryos was inevitable and could be done responsibly, as have also concluded several recent bioethics reports.

Hours before him, Dr. George Daley, dean of Harvard Medical School, called for the establishment of "standards of assessment of the practitioner's competence" of publishing. CRISPR embryos. "People have the right [to do this] must be experts, must be trained, "he said. But he expressed some polite impatience: "It's time to move on. [debates about] possible ethics to chart the path of clinical translation … to advance this technology. "

Referring to a seemingly unauthorized and largely unregulated research, Daley said, "The fact that the first case of human germ line modification was presented as a misstep should not allow us to pinch our head in the sand. … I do not think that a single practitioner who goes against the standards of the field represents a failure of scientific self-regulation. "

A few minutes later, however, biologist Kathy Niakan described experiments revealing a large red flag regarding the use of CRISPR-Cas9 in embryos. She uses this technique (in donated IVF embryos, with no intention of establishing a pregnancy) to disable certain genes and learn what role they play in early human development.

According to unpublished data that she has presented, the technique causes what she delicately calls "complexities", that is, CRISPR-Cas9 strikes the gene that it was supposed to possess, but in addition to modifying it as expected, it caused significant DNA deletions and loss or gain of segments on the chromosome (6, in this case) that contains the targeted gene .

"This is a new important precaution" for the editing of embryo genomes, said Niakan.

if ( 'object' === typeof mc4wp && mc4wp.forms ) { mc4wp.forms.on( 'subscribed', function() { // Successful MC4WP newsletter signup AJAX form submission. fbq( 'track', 'Lead' ); } ); } } );
Source link