AIDS Breakthrough: How CRISPR Gene Editing Successfully Eliminated HIV Infection in Animal Models

A team led by researchers from Temple University's Lewis Katz School of Medicine (LKSOM) and the University of Pittsburg has successfully eliminated HIV infection in animal models using a gene editing technique known as CRISPR.

Their research, described in a paper published in the journal Molecular Therapy, is the first ever to use CRISPR to remove HIV infection in three different animal models, including a "humanized" model or mice that were transplanted with human immune cells and infected with the virus.

"Over our years of research, all of this was frankly a big surprise. This research, so far, has yielded all pleasant surprises, frankly," said Kamel Khalili, director of Temple's center for neurovirology and co-senior author of the study, in a report from CBS News. "I never thought that this CRISPR system was going to be working out so beautifully with such efficiency and precision when it first came onto the scene."

In their first animal model, the researchers genetically inactivated HIV-1 in transgenic mice, leading to roughly 60 percent to 95 percent reduction in the RNA expression of the viral genes.

The researchers then tried the gene-editing CRISPR technique in mice acutely infected with EcoHIV, the mouse equivalent of human HIV-1. They observed that the CRISPR strategy was able to block the viral replication of EcoHIV, with excision efficiency reaching up to 96 percent.

For their third model, the researchers used humanized mice engrafted with human immune cells and infected with HIV-1. Surprisingly, viral fragments of HIV-1 were successfully excised from the latently infected human cells engrafted in mouse tissues and organs.

To monitor HIV-1 replication in real time and observe viral reservoirs in latently infected cells and tissues, the researchers used a novel and cleverly designed live bioluminescence imaging system developed by Dr. Won-Bin Young while at the University of Pittsburgh.

With the success of the CRISPR strategy in mouse models, the researchers plan to replicate their results on primates, whose DNA is much closer to humans.