Worldwide there are about 34 million people living with HIV or AIDS. Of that number two million of them are children.
HIV and AIDS research breakthrough
Scientists recently released information on a breakthrough in HIV research. In a cooperative study, researchers from Imperial College London and Harvard University worked on the project. Their investigation centers around the structure of an enzyme called integrase, which is the “glue” that HIV uses to paste a copy of its genetic information into the DNA of its victim.
Dr. Peter Cherepanov, the lead author of the study from the department of medicine at Imperial College London says, “It is a truly amazing story. 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.”
But this group of researchers decided to start at the beginning again, this time looking for a better model of HIV integrase. “Despite painstakingly slow progress and very many failed attempts, we did not give up and our effort was finally rewarded,” he says.
It took four years and 40,000 trials, but the researchers were able to grow seven kinds of crystals. Out of the seven, only one of these was of sufficient quality to allow determination of the three-dimensional structure of integrase. The only way scientists can determine the structure of this molecular machinery is to obtain high-quality crystals. For the new study, researchers grew a crystal using a version of integrase taken from a retrovirus called Prototype Foamy Virus. Scientists were confident that this integrase and its function were similar enough to HIV integrase to get the answers for which they were searching.
After growing crystals in the lab, the researchers used a giant synchrotron machine at the Diamond light Source in South Oxfordshire to collect X-ray diffraction data from the crystals, enabling them to determine the elusive structure. The investigators then soaked the crystals in solutions of integrase inhibiting drugs, observing for the first time how antiretroviral drugs bind to and inactivate integrase.
The practical application
The new research shows that retroviral integrase has quite a different structure from that predicted by earlier research. Antiretroviral drugs for HIV work by blocking integrase, but understanding of how the medications worked was still lacking. Now with the success of this study, scientists will have a better understanding of how the medications are working, how to stop HIV from developing resistance to the drugs and how to improve on them.