Researchers find out better treatment for HIV

Group researchers have made a breakthrough in HIV research that had eluded scientists for over 20 years, potentially leading to better treatments for HIV.

The researchers have grown a crystal that reveals the structure of an enzyme called integrase, which is found in retroviruses like HIV. When HIV infects someone, it uses integrase to paste a copy of its genetic information into their DNA.

Researchers can only determine the structure of this kind of molecular machinery by obtaining high quality crystals. Researchers grew a crystal using a version of integrase borrowed from a little-known retrovirus called Prototype Foamy Virus (PFV). Based on their knowledge of PFV integrase and its function, they were confident that it was very similar to its HIV counterpart.

Over the years, the researchers carried out many trials, out of which they were able to grow just seven kinds of crystals. Only one of these was of sufficient quality to allow determination of the three-dimensional structure. After growing the crystals in the lab, the researchers used the giant synchrotron machine to collect X-ray diffraction data from these crystals, which enabled them to determine the long-sought structure. The researchers then soaked the crystals in solutions of the integrase inhibiting drugs Raltegravir (also known as Isentress) and Elvitegravir and observed for the first time how these antiretroviral drugs bind to and inactivate integrase.

The study shows that retroviral integrase has quite a different structure to that which had been predicted based on earlier research. Availability of the integrase structure means that researchers can begin to fully understand how existing drugs that inhibit integrase are working, how they might be improved, and how to stop HIV developing resistance to them.