A Peking University-led team of researchers has attempted to cure a patient of HIV by altering stem cells the patient was treated with using the CRISPR gene-editing tool, the Associated Press reports.
The AP notes that while the team wasn't successful in curing the patient, it showed that its approach was precise and safe. "It's not a home run at this point, but getting to first base is really critical for this technology," the University of Pennsylvania's Carl June tells NPR.
Peking's Hongkui Deng and his colleagues attempted to recreate the experiences of the Berlin and London patients, who were effectively cured of HIV after receiving stem cells from people with natural CCR5 mutations that make then resistant to the virus, NPR says.
As the researchers report in the New England Journal of Medicine, they transplanted hematopoietic stem and progenitor cells that had undergone CRISPR-based CCR5 editing into a patient with HIV and acute lymphoblastic leukemia. While they were able to achieve long-term engraftment of these edited cells, they only made up between 5 percent and 8 percent of blood cells. A higher percentage is needed for this to be an HIV cure, June tells the AP.
Deng adds at the AP that their results demonstrate a proof-of-principle. Testing, the AP notes, indicated no unintended editing of other genes.
This, NPR points out, differs from what He Jiankui sought to do. He, who was widely criticized by the scientific community, tried to edit the CCR5 gene in twin girls as embryos to make them resistant to HIV. But, as scientists noted at the time, it was uncertain the approach would work and it was unnecessary as there are other means of preventing HIV.