Temple University researchers on Monday said they had used a gene-editing technique to snip out HIV DNA from the genetic code of mice, bolstering the hope that the infection can be cured.
The work, done with University of Pittsburgh scientists and published in the journal Molecular Therapy, builds on several years of Temple experiments that initially showed the AIDS virus could be cut from cells in lab dishes.
A permanent cure for HIV has been elusive because the virus can maintain a simmering reservoir of infection in certain cells. Antiviral drugs suppress replication so that only a tiny minority of immune cells have the infection, but if the drugs are stopped, the latent virus can break out and resume its destructive course.
The new study is the first to demonstrate that HIV replication can be shut down and the virus eliminated from animal cells by using the gene editing technology, called CRISPR/Cas 9. It combines a synthetic "guide RNA" — a genetic analogue of the search function in a word processor — with an enzyme that acts like a molecular scissors.
The study, co-led by Kamel Khalili, director of Temple's center for neurovirology, successfully used the gene editing strategy in two mouse models — one representing a newly acquired infection, when the virus is actively replicating, the other representing chronic, or latent, infection.
The next step would be to repeat the study in primates such as monkeys, because they more closely mimic human HIV infection, Khalili said in a news release.
CRISPR technology is barely six years old and has not been used in humans. Last year, a federal advisory panel approved a University of Pennsylvania proposal to use CRISPR to engineer immune cells to fight certain types of cancer, but the trial must still be approved by the U.S. Food and Drug Administration.
The ability to precisely edit genes is seen as a potentially revolutionary medical tool, and progress in the field is accelerating. For example, Pitt on Monday announced that it had used CRISPR in mouse models to cut out cancer "fusion" genes — separate genes that fuse and promote malignancy — thereby combatting liver and prostate cancers.