For the first time ever, scientists have completely eliminated HIV in living animals using a gene editing technique.
Three groups of mice were infected with the virus, one with HIV-1, another with EcoHIV (mouse version of the virus), and the third was a ‘humanised model’ which was implanted with human T-cells where HIV tends to hide and avoid detection.
U.S researchers made the breakthrough accomplishment of removing the HIV DNA from human cells implanted into the mice.
This discovery paves the way for human trials because it is the first time scientists have ever achieved complete elimination.
Dr Wenhui Hu, leading the research at the Lewis Katz School of Medicine, said:
Our new study is more comprehensive. 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.
The DNA editing technique, called CRISPR/Cas9, works like a biological version of a word processing programme’s ‘find and replace’ function.
A cell is transfected with an enzyme complex that includes a guide molecule, a healthy DNA copy and a DNA cutting enzyme and the defective DNA strand is targeted.
When treating the first group, the scientists genetically inactivated the HIV-1, reducing the expression of viral genes by up to 95 per cent.
The second group, with the EcoHIV, was more challenging because the virus was more prone to spread and multiply quickly.
Despite this, the strategy eliminated 96 per cent of EcoHIV from the mice.
In the final group, which ‘carry latent HIV in the genomes of human T cells where the virus can escape detection’, scientist managed to completely remove viral fragments from the human cells embedded in mouse tissue.
The next stage of the testing would be to repeat the study in primates where the DNA is much closer to that of humans in order to detect whether the HIV-1 DNA is eliminated in latently infected T cells and other sanctuary sites.
The step after that, after a lot more testing, would be to try the gene editing on humans.
This new research marks a major step toward finding a permanent cure for the HIV virus.
