Source: University of Southern California
Date: July 6, 2010
Summary:
Researchers at the Keck School of Medicine of USC successfully have transplanted blood stem cells modified to be resistant to HIV into mice, allowing the animals to control HIV infections. If the approach can be translated to human patients, it would enable the long-term generation of HIV-resistant T cells in a patient’s body, and the potential for the patient’s own cells to suppress HIV. The strategy is explained in a new study published online in the journal Nature Biotechnology.
The approach targets a gene called CCR5, one of the two gateway molecules that HIV uses to enter human cells. Cannon’s strategy arose from the observation that people with a mutation in a gene called CCR5 are naturally resistant to infection with the most common strains of HIV and do not develop AIDS.
The team used enzymes called zinc finger nucleases — which physically cut DNA — to knock out the the CCR5 gene in human blood stem cells. The researchers transplanted these modified stem cells into mice, where they developed into mature cells of the human immune system, including the T cells that HIV infects. When the researchers then infected the animals with HIV, they found that the mice were able to maintain normal levels of the human T cells and suppress HIV to very low levels, unlike control mice that received unmodified stem cells.
