The human immunodeficiency virus (HIV), which causes AIDS, has claimed about 25 million lives since it was discovered in the 1980s. A cure for this virus has not yet been developed, but scientists are continuously studying the cells and blood samples of people with HIV.
Researchers from the Lewis Katz School of Medicine at Temple Univesity (LKSOM) are working on a new gene editing technique that can snip out the virus from infected cells. This specialized gene editing system may open a way to an eventual cure for people who are infected.
Scientists say that in three years there may already be a cure to HIV.
Antiretroviral drugs can control HIV infection, but patients who stop taking the drugs may suffer a rapid rebound of HIV replication.
Once CD4+ T cells are infected, eliminating the virus becomes difficult. Previous approaches have so far been focused only on the deliberate reactivation of the virus. This process of cell reactivation aims to stimulate an immune response strong enough to start killing HIV.
For their part, however, Dr. Kamel Khalili, senior investigator of the study from LKSOM, and his colleagues, have tried a different approach. Using a tailored gene editing system, they specifically targeted the HIV-1 DNA.
Crispr/Cas9 protein is added to the blood extracted from a person with HIV. The gene editing technique is guided by RNA, which locates the HIV-1 in the T cell genome. The nuclease enzyme, which acts as a "scissor," will edit the HIV-1 DNA, snipping out the virus. The loose ends of the edited HIV-1 DNA will reunite with other loose ends through the help of the DNA's own repair mechanism.
The team also used a gold standard genomic assessment known as ultra-deep whole-genome sequencing to analyze HIV-1 eradicated cells for any sign of mutation. The study showed that these HIV-1-eradicated cells multiply and function normally.
"They demonstrate the effectiveness of our gene editing system in eliminating HIV from the DNA of CD4 T-cells and, by introducing mutations into the viral genome, permanently inactivating its replication. Further, they show that the system can protect cells from reinfection and that the technology is safe for the cells, with no toxic effects," said Dr. Khalili.
Dr. Khalili's team believes that even with just 20 percent of immune cells replaced, the method can cure HIV.
"The findings are important on multiple levels," Dr. Khalili added.
Photo: NIAID | Flickr
