Researchers at the Istituto Superiore di Sanità (the Italian Institute of Health) have discovered a method for removing latent HIV genes from human cells. The technique, uncovered by Enrico Garaci, president of the institute, and Andrea Savarino, a retrovirologist, may make it possible to overcome the ‘barrier of latency’, by which HIV remains in an inactive state, preventing the virus from being eradicated from the body.
Savarino’s team aimed to label the virus so that cells with the latent infection can be targeted by the immune system, or by immunotherapy. While it is known this can be achieved using inhibitors of histone deacetylases (HDACs), a class of enzymes that maintain HIV latency, to date they have only been shown to be effective at toxic doses.
The Italian researchers tested a collection of HDAC inhibitors, adding buthionine sulfoximine (BSO), a drug that induces oxidative stress. BSO prompted cells that are normally unresponsive to the HDAC inhibitors into responding, triggering apotosis (cell death). Cells that were not infected with latent HIV were left intact by the drug combination.