Chinese Scientists Have Tried to Cure HIV with CRISPR Gene Editing: 'The Genie Is out of the Bottle'

Scientists in China have used the CRISPR gene-editing technique to try to cure a man of HIV, in what one expert called an "important step" forwards in treating disease.

Hailed as a revolutionary leap forward for conducting research and finding potential treatments for disease, CRISPR makes it quicker and easier to edit DNA. The technique called CRISPR-Cas9 involves using the Cas-9 protein to snip at a specific part of DNA.

Researchers used CRISPR to edit a donor's stem cells and transplant them into a 27-year-old patient with HIV and leukemia. They hoped the cells would survive, replicate, and cure the man of HIV.

The approach involved knocking out the CCR5 gene in the donor's stem cells. CCR5 encodes a protein that HIV uses to get inside human blood cells—and past research has shown those with a mutation on the gene are protected from HIV.

The team was able to edit 17.8 percent of a donor's stem cells, and the gene-edited cells were still working 19 months after they were transplanted. However, they made up five to eight percent of the recipient's stem cells. Just over half of the edited cells had died away.

The team were pleased to find the man didn't appear to suffer any adverse effects linked to the transplant. The findings were published in the New England Journal of Medicine.

The work was inspired by the treatment of Timothy Ray Brown. Known as the Berlin Patient, Brown had leukemia and HIV and received a stem cell transplant to treat his cancer in 2007, and once more in 2008. His donor had a mutation on the CCR5 receptor, which makes an individual immune to HIV. Brown is thought to be the first person cured of HIV. Scientists have been trying to replicate this cure without success.

Hongkui Deng, a biologist at Peking University in Beijing who led the study, told Newsweek he was also one of the researchers that identified the role CCR5 plays in HIV infection in 1996.

"It was quite exciting that it was me to complete the cycle," he said.

Deng told Nature: "This was the first trial, so the most important thing was to test safety."

"Our results show the proof of principle," he told Newsweek. Deng said he hopes the approach could also be used to treat other diseases.

Carl June, professor of immunotherapy at the University of Pennsylvania wrote an editorial in the New England Journal of Medicine critiquing the work.

He told the Associated Press: "They need to approach 90 percent or more, I think, to actually have a chance of curing HIV." It was positive that the scientists did not make a "Frankenstein cell" that would affect other genes instead of the intended target, he told the news agency.

Fyodor Urnov, a biomedical scientists at the University of California, Berkeley who did not work on the study told Nature: "This is an important step towards using gene editing to treat human disease. I'm not surprised that five percent was not enough to lower the viral load, but now we know that CRISPR-edited cells can persist, and that we need to do better than five percent.

"Because of this study, we now know that these edited cells can survive in a patient, and they will stay there."

June told the Associated Press the approach appeared to be safe and precise, and it raised no ethical concerns.

In the NEJM editorial, he argued it was "striking" how quickly the team went from a proof of concept in animals to a trial in a human in two years. Such a process would take five years in the U.S., he said.

"This may be an indication that the regulatory environment in China permits more rapid translation than that in the U.S.," he wrote.

"HIV–AIDS has been at the vanguard of cell and gene therapy for decades, and this trend has continued in genome editing. In any case, the genie is out of the bottle with genome editing."

Last year, a Chinese scientist was internationally condemned for creating the world's first genetically edited babies over fears problems could be passed on to their children and beyond.

He Jiankui, an associate professor at the Southern University of Science and Technology in the Guangdong province, knocked out CCR5 of seven human embryos in an IVF clinic, in an attempt to make the resulting children resistant to HIV. His experiments resulted in the birth of two twin girls.

But He stood by his work, and said he was "proud" of what he had done, BBC News reported.

This article has been updated with comment from Hongkui Deng.