About 1.2 million people are estimated to be infected with HIV in the United States. The infection is fatal for those who eventually develop AIDS. An existing medical technology though potentially offers a cure.
In a new study published in the journal Molecular Therapy, researchers have made important strides toward finding a treatment for HIV, one that can eliminate and not just suppress the virus, using the controversial gene-editing technology CRISPR.
The gene-editing tool allows scientists to essentially cut out and insert portions of the DNA. It works like a pair of microscopic scissors that can snip out unwanted portions of the DNA and replace them with a new one.
CRISPR pertains to a specific repeating sequence of DNA extracted from a single-celled organism that pairs up with an RNA-guided enzyme known as Cas9. The RNA latches into the Cas9 enzyme. Together, the two look for the virus that matches the code they have been programmed to find and once the virus is located, the Cas9 will cut it and destroy it.
In new experiments with mice, researchers were able to successfully remove most of the infection from the animals demonstrating the potential capability of the technology in treating HIV.
Treating HIV With Gene-Editing Technology
Currently available drugs work by preventing HIV from replicating itself and stopping the progression of the disease. The problem with these medications is they need to be continuously taken for them to remain effective. With the gene-editing technology, scientists may be able to eliminate the root cause of the virus.
For the study, researchers involved three animal models, which include the "humanized" model, where HIV-infected human immune cells were transplanted into the mice.
The researchers demonstrated that the technique works for active and dormant forms of the virus, which is important since viruses that may not be actively replicating may become active.
The latent form of the disease is harder to track in cells. When treatment inactivates the virus, it can hide in the immune system and just wait for the perfect condition to resurface. This means that patients need to be on medication for their entire lives since the latent HIV can activate once the treatment is stopped.
"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," said study researcher Wenhui Hu, from Temple University Lewis Katz School of Medicine.
In their mice study, Hu and colleagues successfully removed the virus from parts of the lungs, heart, colon, spleen and brain with just a single injection of the gene-editing protein.
"The basic science community in HIV research is now very focused on finding a cure," said Paul Voldberding, from amfAR Institute for HIV Cure Research. "It still feels a long way off but the tools we now have definitely including the gene editing used in this report is accelerating our work and raising optimism."