For the first time, researchers have used the CRISPR technique to successfully remove HIV genes from the genomes of animals infected with the retrovirus. Before this breakthrough, the HIV virus proved impervious to gene editing, due to its tendency to accumulate mutations.
“In a proof-of-concept study, we show that our gene editing technology can be effectively delivered to many organs of two small animal models and excise large fragments of viral DNA from the host cell genome,” said Kamel Khalili of the Comprehensive NeuroAIDS Center at Temple University. Khalili’s work is promising: using CRISPR, the viral DNA was removed from over 50 percent of the cells studied.
Khalili and his team conducted their research using mice and rats who were engineered to integrate HIV genes into every cell type. Using the precision DNA editing technique known as CRISPR, the researchers removed those HIV genes from multiple cell types, including the brain, ear, liver, kidney, lungs, spleen, and even blood. The results of the study were published in the journal, Gene Therapy.
Khalili and his team previously used the CRISPR technique in vitro to remove HIV genes from cells collected from HIV-positive patients. Now that the researchers have demonstrated the gene editing tool’s effectiveness in vivo, CRISPR could eventually be developed as a potential treatment for patients with HIV.
“If this technology gets into the clinic to treat human patients, it’s not going to be very complicated,” said Khalili. “You don’t have to bring the patient to the clinic and do a bone marrow transplant or all kinds of complicated technology. You can basically apply this to any setting.”
For now, the researchers are working on identifying the ideal dosage for the technique, and monitoring their animal models for any signs of side effects. According to Khalili and his team, the risk of off-target gene editing and other adverse events is low, because the CRISPR molecule used specifically targets HIV DNA.
“The first step is to permanently inactivate those viruses incorporated in cells,” said Khalili. “If we can do that, and reach that level, then we may be able to functionally cure individuals or have a sterilizing cure.”