Researchers in the UK have discovered a gene which may stop HIV spreading after it enters the body.
A study by King’s College London found the gene MX2 could be a new target for effective, less toxic treatments to combat the virus.
The scientists described the findings as “extremely exciting” but campaigners said that while it was promising work, much more research was needed to develop treatments.
Figures show that hundreds of cases of HIV continue to be diagnosed each year in Scotland.
Health Protection Scotland said 349 cases were diagnosed in 2012, and 177 so far this year.
More than 4,500 HIV-infected patients are thought to live in Scotland, but concerns remain that many people with the virus remain undiagnosed. While improved treatments have dramatically improved long-term survival, the search has continued to find drugs with fewer side-effects.
The latest study, published in the journal Nature, is the first to identify a role for the human MX2 gene in inhibiting the spread of HIV.
Researchers said the gene could be used in treatments which “mobilised” the body’s natural defences against the virus. The scientists, led by Dr Caroline Goujon and Professor Mike Malim at the department of infectious diseases, carried out experiments on human cells in the lab, introducing the virus to two different sets of cells and observing the effects.
In one group of cells, the MX2 gene was expressed or “switched on”, while in the other set it was not, or “silenced”, to stop it working. The scientists saw that in the cells where MX2 was silenced, the virus replicated and spread. But in the cells where the MX2 gene was switched on, the virus was not able to replicate and new viruses were not produced.
Professor Malim said: “This is an extremely exciting finding which advances our understanding of how HIV virus interacts with the immune system and opens up opportunities to develop new therapies to treat the disease. Until now, we knew very little about the MX2 gene, but now we recognise both its potent anti-viral function and a key point of vulnerability in the lifecycle of HIV.”
Prof Malim said developing drugs to stimulate the body’s natural defences was a very important approach because they would be triggering a natural process and therefore would not have the problem of drug resistance.
“There are two possible routes – it may be possible to develop either a molecule that mimics the role of MX2 or a drug which activates the gene’s natural capabilities,” he said.
“Although people with HIV are living longer, healthier lives with the virus thanks to current, effective treatments, they can often be toxic for the body and drug resistance can become an issue with long-term use.
“It is important to continue to find new ways of mobilising the body’s natural defence systems and this gene appears to be a key player in establishing viral control in people with HIV.”
Jason Warriner, clinical director at the Terrence Higgins Trust, said: “Gene therapy is a promising new avenue that might one day help people manage HIV without daily medication. However, it’s still very early days.
“Fortunately, existing treatments are already very good.”