A major impediment to curing patients with HIV is the fact that the virus integrates its DNA into the genome of the cells it infects. While antiretroviral drugs and therapies can prevent infection of new cells and kill cells that are actively producing virus, a "latent reservoir" remains that can cause an active infection to re-emerge after drug treatment has stopped. Therefore, current treatments for HIV-infected individuals requires them to take antiretroviral drugs for their entire lives.One approach that various groups are exploring to attempt to rid the body of these latent reservoirs is to use CRISPR gene editing technology to cut the virus out of infected cells. Recently, researchers published a study in which they performed a proof-of-principle experiment showing that they could use CRISPR to cut HIV out of infected mice (mice cannot normally be infected with HIV, a human virus, so the researchers used mice that had been engineered to carry humanized cells that are susceptible to HIV infection):Yin et al. In Vivo Excision of HIV-1 Provirus by saCas9 and Multiplex Single-Guide RNAs in Animal Models. Mol Ther. 25 (2017). Published online 30 March 2017. doi:10.1016/j.ymthe.2017.03.012 See also the accompanying commentary article: http://www.sciencedirect.com/science/article/pii/S1525001617301703 The work builds off of previous studies by the same group showing that the virus could be cut out of human cells in the laboratory . The researchers also published a smaller-scale demonstration in 2016 . Their study engineers a virus (the normally non-pathogenic adeno-associated virus) to deliver CRISPR throughout the body. They are able to detect successful cutting of the virus at various sites in the infected mice's bodies.Still, much more work needs to be done before this work could be applied to AIDS patients. Curing patients of HIV infection is a very difficult task as it requires eliminating all latent reservoirs. While the researchers show that they can detect successful cutting of the latent provirus in various cell types, they do not show evidence that their therapy removes all proviruses or that their delivery system can target all cells that may be harboring the latent HIV reservoirs. It will likely be very difficult for the researchers' method to eliminate 100% of the virus, and testing the ability of their delivery method to target all infected cells will be particularly difficult as mouse models of HIV may not harbor the same types of reservoirs present in humans. Still, the research represents an important step forward in developing CRISPR technology into a potential cure for HIV.(Thanks to @mfb to pointing the study out to me)