HIV and subsequent AIDS is one of the most debilitating diseases known to modern humans affecting approximately 35.3 million people world wide (1). Great strides have been made in controlling the disease and in potentially curing the disease but these often involve cocktails of strong drugs or bone marrow transplants and there is still currently no vaccine for HIV or way to prevent infection in the first place. There is, however, a group of people who are naturally resistant to HIV infections or have a slower progressing infection (2). These people have a mutation within a protein that the HIV virus needs to use to enter the white blood cells. This protein is known as C-C chemokine receptor 5 (or CCR5). This mutation is found within 10-15% of Europeans (2), but is sadly absent from some of the most HIV vulnerable populations in the world. Wouldn’t it be great if we could find a way to use this natural resistance to help prevent HIV infections?
A recent research article from a group in San Francisco has developed a way to introduce this naturally occurring mutation into stem cells that can then be turned into resistant white blood cells (3)(4). The introduction of white blood cells with this mutation has already potentially cured one patient after they received a bone marrow transplant from someone who had this natural resistance. The new research would allow for resistance in all HIV patients without the need for transplants from people with this natural resistance (as they are hard to find). Using a type of stem cell (induced pluripotent stem cells or iPCS) made from patients’ own cells, they were able to delete part of the protein that then makes it resistant to HIV attachment. Once these stem cells were allowed to develop into full-grown white blood cells, the researchers saw that they were resistant to HIV viral infection. This research has far reaching benefits if the treatment proves to be safe. Some of the concerns that should be raised are whether these iPCS’s are safe to use in patients and whether the genetic manipulations done are safe. It is also relatively unknown how this naturally occurring mutation affects the normal function of white blood cells. If these white blood cells were prevented from performing their normal function then you would not want to introduce them into a patient with HIV. However, research so far seems to indicate that the white blood cells with this mutation are essentially unaltered. If these results can hold up to more research it would mean a huge step forward in the prevention and potentially elimination of HIV epidemics worldwide.
1) HIV/AIDS. World Health Organization. http://www.who.int/gho/hiv/en/
2) HIV Resistant Mutation. Nature Publishing Group. http://www.nature.com/scitable/blog/viruses101/hiv_resistant_mutation
3) Seamless modification of wild-type induced pluripotent stem cells to the natural CCR5Δ32 mutation confers resistance to HIV infection. Lin Ye, Jiaming Wang, Ashley I. Beyer, Fernando Teque, Thomas J. Cradick, Zhongxia Qi, Judy C. Chang, Gang Bao, Marcus O. Muench, Jingwei Yu, Jay A. Levy, and Yuet Wai Kan. PNAS. 2014. http://www.pnas.org/content/early/2014/06/04/1407473111
4) Gene editing tool can write HIV out of the picture. New Scientist. http://www.newscientist.com/article/dn25698-gene-editing-tool-can-write-hiv-out-of-the-picture.html#.U5fVQo1dW6U