Previous studies in rats and mice have shown that gene editing through CRISPR-Cas9 technology is capable of removing HIV DNA from genomes that hold the virus, successfully cutting large fragments of HIV DNA from infected cells and inhibiting viral gene expression. If it is stopped, HIV rebounds, renewing replication and fueling the development of AIDS.
HIV rebound is directly attributed to the ability of the virus to integrate its DNA sequence into the genomes of cells of the immune system, where it lies dormant and beyond the reach of antiretroviral drugs.
The results are proof that elimination of HIV is possible-but they're just a first step, not a leap straight to cure, he cautioned. However, it is unclear whether this treatment will cure HIV in human beings.
If their methods continue to prove successful, clinical trials could follow as soon as next summer, he said. In the combo group, LASER ART was given used to suppress HIV growth, and then CRISPR was used to eliminate the remaining HIV DNA.
Snow said, "It's always incredibly exciting to see to see breakthroughs in the fight of HIV/AIDS, as a person living with HIV, I'm thrilled that there's a tremendous effort around the world to find a scientific cure, and actual cure". In 1984, Dr. Gallo co-discovered HIV as the cause of AIDS.
The virus is at present treated with antiretroviral therapy (ART), which suppresses it from replicating and prevents many patients within the USA from developing AIDS. LASER ART was used to keep replication of the virus at low levels for an extended period of time.
It combines this with a recently developed therapeutic strategy known as LASER (long-acting slow-effective release) ART. The long-lasting medications were made possible by pharmacological changes in the chemical structure of the antiretroviral drugs. However, research on animals may not produce the same results in humans. Overall, it reduces the need for ART administration over time.
The team modified the drug for a slow release across several weeks, targeting tissue in the spleen, bone marrow and brain where latent HIV reservoirs, or clusters of inactive HIV cells, were likely to occur. But this approach, like ART, wasn't able to completely eliminate the virus on its own. Once infection was established, mice were treated with LASER ART and subsequently with CRISPR-Cas9.
An worldwide team of virologists were able to destroy all trace of HIV in the cells of the two "humanized" mice with the genomic editor CRISPR/Cas9.
"The big message of this work is that it takes both CRISPR-Cas9 and virus suppression through a method such as LASER ART, administered together, to produce a cure for HIV infection", Dr. Khalili said.
"Over the years, we have looked at HIV as an infectious disease".
What we really need is a therapy that completely eliminates HIV from the body, which is precisely what Khalili and his colleagues have been working on for the past several years.
"We now have a clear path to move ahead to trials in nonhuman primates and possibly clinical trials in human patients within the year", added Khalili, who also directs Temple's neurovirology center and its neuroAIDS center.