Blood Stem Cells Made Resistant to HIV

Researchers at the University of Southern California disrupted a gene in human blood-forming stem cells and made the cells resistant to infection by HIV. Equally important, the disruption of the gene HIV uses to invade cells did not alter the cells’ stemness; they were able to replicate as stem cells and differentiate into various blood cells. The latter is crucial for the goal of creating a long-term cure for AIDS that would allow patients to stop their medications.

The work seeks to replicate the situation of the “Berlin Patient” who appears to have been cured of both his HIV and lymphoma by receiving a bone marrow transplant of stem cells from a donor that had a naturally occurring mutation to the same gene, known as CCR5.

The researchers proved the genetically modified cells could resist HIV infection by injecting them into mice bred to tolerate human tissue. Those mice fought off infection and were able to produce new resistant blood cells.

In a press release from USC lead research Paul Cannon said:

“This hybrid of gene and stem cell therapy shows that it is possible to create HIV-resistant immune cells that can eventually win the battle against HIV in vivo.”

The team disrupted the CCR5 gene using a chemical trick called “zinc finger” technology developed by Sangamo BioSciences. In a press release the company said the approach:

“enables the permanent disruption of the CCR5 gene.”

Both Sangamo and Dr. Cannon are part of a $14.5 million CIRM Disease Team project that aims to move this work into human patients.

This video describes the work of the disease team:

The current research was published in the July 2, 2010 issue of Nature Biotechnology.

D.G.