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Thursday, June 12, 2014

Gene editing could make humans resistant to HIV

A new genetic engineering tool can help give cells a rare mutation that prevents them from being infected with HIV.

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Image: CDC
The technique, which is still in experimental stages, takes advantage of a rare mutation that makes one percent of people of European descent resistant to HIV.
Using a new “genome editing” tool, researchers are hoping to be able to insert the mutation into the cells of other people - and they’ve already proved the basic principles work using induced pluripotent stem cells (iPSCs), Peter Aldhous reports for New Scientist.
The new genome editing technique is much more precise than tradition forms of genetic engineering, as it places a sequence of gene into a pre-designated area of the genome, rather than at random locations.
By using this technique, researchers led by Yuet Kan from the University of California, San Francico, have managed to alter the genome of iPSCs, which can turn into any cell in the body. As predicted, when the scientists grew these iPSCs into white blood cells, they were resistant to HIV.
Their research is published in the Proceedings of the National Academy of Sciences.
The mutation they’re implanting causes people to carry two copies of a mutated gene for a protein called CCR5, which the HIV virus has to lock onto before it can invade white blood cells. The mutation prevents it from doing that.
The research was inspired by a man called Timothy Ray Brown, who was famously “cured” after receiving a bone marrow transplant from a naturally HIV-resistant person. This new technique would work in a similar way, but without the need for someone else’s bone marrow.
However, although it works in the lab, there is still a long way to go before the treatment could be used in humans. 
The researchers now plan to turn the iPSCs into blood-forming stem cells, which, when transplanted into a patient, would give rise to all the different types of blood cells - including the specific white blood cell attacked by HIV.
It’s a pretty exciting first step, and we can’t wait to see what happens next.
Source: New Scientist