Researchers find three genes resistant to HIV
International researchers, co-led by a Swiss team, have discovered three genes in the DNA of HIV-infected patients that offer protection against the virus.
They say the findings should aid the search for a vaccine to boost the effects of the genes and help the body’s immune system overcome infection.
The results, published on Thursday in the journal Science, stem from the first ever study analysing how the human genome responds to the virus that causes Aids.
“We found three genes that were very powerful against the virus. If you have the good luck to have these gene variants, they will protect you from the virus,” Amalio Telenti of Lausanne University’s institute of microbiology told swissinfo.
Researchers in Lausanne and Geneva analysed the genetic make-up of 486 patients, screening blood samples for more than half a million variants to produce a “bar code” for each individual.
The data was sent to the United States where the genes were ranked in a “hit parade” according to their capacity to fight off the virus.
“People have very different abilities of controlling the virus naturally. Clearly there is a human impact and we need to find the key to imitate this,” explained Telenti.
The Lausanne professor heads the European arm of a vast genetic research project run by the Center for HIV/Aids Vaccine Immunology (Chavi) at Duke University in the United States, which has a seven-year, $300-million (SFr360 million) budget to help develop a vaccine.
Immune system
Two of the variants were found in genes controlling the human leukocyte antigen (HLA) system, which plays a major role in the immune system by identifying foreign invaders and tagging them for destruction.
Those behind the Chavi study say the latest findings will greatly increase the knowledge of why patients differ in how well they control the virus.
“There are some things that are useful for the pharmaceutical industry and others that are useful for science,” said Telenti. “It’s up to the people coming after us to examine the list and decide what use to make of the more interesting genes.”
He added that virologists and immunologists were already “very excited” about one of the genes as a potential vaccine target.
It is not the first time that a gene capable of blocking HIV has been found. One called CCR5 was pinpointed in 1996 and a vaccine is currently awaiting regulatory approval.
swissinfo, Adam Beaumont in Lausanne
The EuroChavi consortium, coordinated by Amalio Telenti, sifted through data collected from more than 30,000 patients.
They arrived at 486 patients who had had multiple blood tests documenting viral loads after infection and before they started receiving antiretroviral treatment.
Patients involved in the study came from Switzerland, Italy, Britain, Australia, Spain and Denmark. The genetic analysis was performed at the universities of Lausanne and Geneva, and Duke University in the US.
The human immunodeficiency virus (HIV) is a retrovirus that infects cells of the human immune system, destroying or impairing their function.
As the infection progresses, the immune system becomes weaker, and the person becomes more susceptible to so-called opportunistic infections.
The most advanced stage of HIV infection is acquired immunodeficiency syndrome (Aids). It can take 10-15 years for an HIV-infected person to develop Aids; antiretroviral drugs can slow down the process even further.
According to the United Nations, an estimated 39.5 million people are living with HIV. Last year 2.9 million people died of Aids-related illnesses.
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