Scientists in China used gene-editing tool CRISPR to treat a patient with HIV. It was the first time that CRISPR was used in an experimental HIV therapy.
No Unintentional Genetic Alterations
It did not cure nor control the patient's HIV infection, but the researchers said that that the treatment appears to be safe.
In the new study published in the New England Journal of Medicine on Sept. 11, Hongkui Deng, from Peking University, and colleagues reported that they did not find any unintentional genetic alteration, a concern associated with gene therapies.
In an earlier controversial study, a Chinese scientist also used CRISPR to edit the genomes of twins to make them resistant to HIV. Jiankui He edited the DNA of the embryos, so the gene alterations may be passed down to the next generation.
The new study is different in that it made the DNA edits on adult cells, which means the changes will not be passed on.
The HIV patient in the experimental treatment also has leukemia and needed a bone marrow transplant. The researchers edited the DNA in bone marrow stem cells from a donor and then transplanted the edited cells into the patient.
The researchers then used CRISPR to delete the gene called CCR5, which gives instructions to the protein on the surface of some immune cells.
HIV uses this protein to get inside cells. People who have a natural mutation in the CCR5 gene are thus resistant to HIV infection.
CRISPR For HIV And Leukemia
A month after the transplant, the patient's leukemia was in complete remission. The genetically edited stem cells increased in the patient's body, produced blood cells, and persisted in the body for the next 19 months.
The levels of HIV in his body, however, increased when he briefly stopped taking the HIV medications as part of the study, so he had to start taking the medications again. The study nonetheless showed of another potential application of CRISPR.
"This plants the flag to say that at least in this one instance, this type of therapy appears safe," said Jennifer Doudna, from the University of California, Berkeley, who is credited as an inventor of CRISPR. "The next step is showing that there is some efficacy, a therapeutic benefit to doing this."