May 1 (UPI) -- Researchers at Temple University and the University of Pittsburgh successfully excised HIV DNA from the genomes of living animals to eliminate HIV-1 infection, the report in a new study.
The team is the first to perform HIV-1 replication and shut down the virus, eliminating it from infected cells in three different animal models, including a "humanized" animal model where mice were transplanted with human immune cells and infected with HIV.
To do this, researchers used the gene-editing technology CRISPR/Cas9 to excise viral fragments from latently infected human cells embedded in mouse tissues and organs. The work continued a previous proof-of-concept study in which they used transgenic rat and mouse models with HIV-1 DNA incorporated into the genome of every tissue of the animals' bodies.
"Our new study is more comprehensive," Dr. Wenhui Hu, an associate professor in the Center for Metabolic Disease Research and the Department of Pathology at the Lewis Katz School of Medicine at Temple University, said in a press release. "We confirmed the data from our previous work and have improved the efficiency of our gene editing strategy. We also show that the strategy is effective in two additional mouse models, one representing acute infection in mouse cells and the other representing chronic, or latent, infection in human cells."
Researchers genetically inactivated HIV-1 in transgenic mice, reducing the RNA expression of viral genes by roughly 60 to 95 percent. They tested their system in mice infected with EcoHIV, which is the mouse equivalent of human HIV-1.
The strategy was 96 percent effective in EcoHIV mice, giving the first evidence for HIV-1 eradication by prophylactic treatment with the CRISPR/Cas9 system.
Researchers determined the success of the strategy by measuring levels of HIV-1 RNA and used a new live bioluminescence imaging system.
The study was published in Molecular Therapy.