HIV researchers are incensed that the first reported use of gene editing in human embryos was aimed at conferring HIV immunity, criticizing the move as reckless and unnecessary.
The Associated Press reported Sunday that twin girls Lulu and Nana were born after a team led by He Jiankui of the Southern University of Science and Technology in Shenzhen, China, edited their genes when they were days-old embryos. Their father reportedly had HIV, and the procedure wiped out a gene that is usually necessary for the virus to infect cells. The news, first reported by MIT Technology Review, broke before the scientist had published any of his data, and was accompanied by YouTube videos in which He described his work.
Genetics experts immediately criticized the project as premature and said it risked conferring dangerous mutations to the twins.
Adding to that chorus, HIV researchers told BuzzFeed News that such a procedure doesn’t make sense for preventing HIV. Targeting and knocking out a single gene, as He claimed to do, does not offer resistance against all strains of the virus. What’s more, there are simpler and less risky ways for people with HIV to have children without transmitting the disease. Critics also said that the move draws additional stigma to people with HIV.
“It’s all such, such bullshit,” said Paula Cannon, a professor of immunology at the University of Southern California’s Keck School of Medicine. “I’m angry on behalf of the genetic engineering community. I’m angry on behalf of the HIV community.”
“It feels a little crazy to have HIV be involved in what appears to be the first-ever attempt to gene-edit a human being from birth,” Richard Jefferys, of the HIV/AIDS advocacy organization Treatment Action Group, told BuzzFeed News. “It just seems all kinds of wrong.”
The researchers said that existing methods already offer parents simple ways to have children without transmitting the disease. “It’s very easy — there’s no reason a HIV-positive man can’t have HIV-negative children,” Cannon said. “Dr. He’s just making up a medical need that is not there.”
For instance, the CDC and World Health Organization have suggested combining in-vitro fertilization and “sperm washing,” in which the semen — which could carry cells infected with the virus — is separated from the sperm cells, which cannot be infected. “There was no need to participate in an experiment involving the gene editing of embryos in order to avoid transmitting HIV,” Jefferys said.
In one of five videos introducing the procedure, He said that pioneering gene-editing trials in the US had already targeted this gene, and suggested that the approach was known and safe.
Cannon refuted that characterization, calling it an “incorrect extrapolation.” She said that other trials that had sought to knock out the same gene, known as CCR5, had significant differences: They included adults who were already HIV-positive and had consented to participate; the editing technique did not use CRISPR or the variation that He used in his work; and crucially, the edits to the genes were made after cells had been isolated from study subjects.
“Nothing from the trials concerns us in terms of safety — but it’s too early to say if CCR5 knockouts, even in HIV-infected individuals, is going to be an effective therapy,” Cannon said.
Among his justifications for picking CCR5 as a worthy target, He said that he was concerned about discrimination that people with the disease faced. “Employers may fire people after discovering their HIV status. Doctors may refuse to treat,” He said. The method may help some “very high-risk families protect their children from this same fate.”
Cannon said that He’s choice actually increased the stigma associated with HIV. “He’s now branding HIV as something so terrible that you, as an embryo, need to be gene-edited to make sure you can’t get it. Please. You could also just educate people, or wear a condom, or if you are at high risk, you can take anti-retroviral medication,” Cannon said.
The technique, even if successful, would not fully protect the girls from infection, the experts said.
Researchers who have been studying HIV elimination for the past few years have zeroed in on CCR5 as a gene of interest because it codes for a protein that most kinds of HIV need to infect cells. But not all strains of the HIV family of viruses use this path. If the twins were exposed to any of these alternative strains, they could still be infected.
“If you have any other flavors of the virus, then knocking out CCR5 is not going to work,” Cannon said.