An Italian scientist has discovered a molecule that may be able to help the body's immune system defend itself from AIDS.
Professor Paolo Lusso of Milan's San Raffaele hospital, who carried out the research with American AIDS expert Anthony Fauci, said the discovery of Interleukin 7's (IL-7) HIV-inhibiting properties could open up a new front in the war on the virus.
At the moment, AIDS is mainly treated with antiretroviral medicines that try to block its development.
Laboratory tests on IL-7, on the other hand, show that this molecule helps immune-system cells CD4 and CD8 - two of the virus' main targets - fend off the disease.
So it is possible that new IL-7-based drugs could be developed to use alongside antiretroviral medicines to attack AIDS from two different directions.
IL-7 is a member of the cytokine family of molecules, which give off signals that enable cells to communicate with each other.
Cytokines are extremely important because their signals trigger the immune system's defences when the body is under attack.
It seems that IL-7 alerts CD4 and CD8 cells to the HIV virus when it tries to enter them and cause them to self-destruct.
Lusso's and Fauci's tests on blood samples taken from 24 AIDS sufferers showed that the presence of IL-7 increased the length of time the immune-system cells survived.
They said the results varied according to the stage of infection and differed from patient to patient. But the immune system was boosted to some degree in all cases.
The results of the study will be published in the next edition of prestigious US journal The Proceedings of the National Academy of Sciences.
Lusso and Fauci said the next stage would be to conduct tests on animals and human volunteers.
Italy has 120,000 people who are HIV positive and about 4,000 new infections every year. Experts say contagion is now almost entirely through unprotected sex, both homosexual and heterosexual.
The United Nations estimates that over 38 million people around the world are HIV positive.
