After 20 years of research, scientists say they have solved a crucial puzzle about the AIDS virus and that these findings could lead to better HIV treatments…
By Militza Richard
British and U.S. researchers announced that they have grown a crystal that allows them to see the structure of integrase, an enzyme found in retroviruses like HIV that is a target for some of the newest HIV medicines.
"Despite initially painstakingly slow progress and very many failed attempts, we did not give up and our effort was finally rewarded," said Peter Cherepanov of Imperial College London, who conducted the research with scientists from Harvard University.
The scientists from Imperial and Harvard explained that having the integrase structure will help researchers to fully understand how integrase inhibitor drugs work. This means researchers can improve the drugs and hopefully stop HIV from developing resistance to them.
When the human immunodeficiency virus (HIV) infects someone, the virus uses the integrase enzyme to paste of copy of its genetic information into the infected person’s DNA, Cherepanov explained in the study published in the Nature journal on Sunday.
Some new HIV drugs, such as Merck & Co’s Isentress and an experimental drug from Gilead Sciences called elvitegravir, work by blocking integrase. However, scientists are not exactly cure how these drugs actually work or how to improve them.
The only way to find out how the drugs worked was by obtaining high-quality crystals. Unfortunately, this project had defeated scientists for many years.
"When we started out, we knew that the project was very difficult, and that many tricks had already been tried and given up by others long ago," said Cherepanov. "Therefore, we went back to square one and started by looking for a better model of HIV integrase which could be more amenable for crystallization."
The researchers grew a crystal using a version of integrase borrowed from another retrovirus very similar to its HIV counterpart. After more than 40,000 trials, the scientists managed to successfully grow a crystal of high enough quality to allow them to see the three-dimensional structure
When testing the Merck and Gilead drugs on the crystals, scientists were able to see how the medicines bind to and block integrase.
Since the beginning of the AIDS epidemic, nearly 60 million people have been infected with HIV and 25 million people have died of HIV-related causes. There is currently no cure and no vaccine, although there are some treatments to keep patients healthy. The United Nations data for 2008 shows that 33.4 million people had HIV and 2 million people died of AIDS in that year. The worst-affected region is sub-Saharan Africa, accounting for 67 percent of all people living with HIV.
Edited by Gabe Perna