By Kristina Dougherty

PHILADELPHIA (CBS) – Researchers at the Lewis Katz School of Medicine at Temple University say they have, for the first time, successfully excised a segment of HIV-1, the virus responsible for AIDS, from the genomes of living animals.

They say they did this by using gene editing technology.

“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,” says Kamel Khalili, PhD, lead investigator on the study.

Researchers say current treatment for HIV is centered around the use of a combination of antiretroviral drugs, and while this can effectively suppress HIV replication, it cannot eliminate HIV-1 from infected cells.

In earlier research, Dr. Khalili and colleagues were able to show that their gene editing system, which is based on CRISPR/Cas9 technology, has the ability to eliminate HIV-1 from infected cells in vitro without an adverse effect on the host cells.

Their latest study, they say, was designed to test whether the gene editing technology could also eliminate HIV-1 in transgenic rats and mice.

Researchers say two weeks after delivering rAAV CRISPR/Cas-9 molecules into the bloodstream, they analyzed the DNA of tissues collected from the animals.

They say the results showed that the targeted segment of HIV-1 DNA had been excised from the viral genome in every tissue.

“The ability of the rAAV delivery system to enter many organs containing the HIV-1 genome and edit the viral DNA is an important indication that this strategy can also overcome viral reactivation from latently infected cells and potentially serve as a curative approach for patients with HIV,” said Dr. Khalili.

Researchers say the excision strategy used, which led to the removal of a large fragment of HIV-1 DNA, eliminates any chance for the development of replication-competent virus.

Dr. Khalili says the next step is to conduct a follow-up study in a larger group of animals, in which the researchers plan to monitor for effects of the treatment, its safety, and other important factors.

The breakthrough is described further online in the journal Gene Therapy.