Genetic cause of innate resistance to HIV/AIDS

July 16, 2008

Some people may be naturally resistant to infection with HIV, the virus that causes AIDS. The results of a study conducted by Dr. Nicole Bernard of the Research Institute of the McGill University Health Centre (MUHC) bring us closer to a genetic explanation. Her study findings were published on July 16 in the journal AIDS.

The simultaneous expression of certain versions of two specific genes called KIR3DL1 and HLA-B*57 is thought to be at the root of some cases of this innate resistance to HIV infection. Depending on which versions of these two genes the patient has, he or she will resist HIV infection or develop AIDS at a slower rate.

These results were obtained by comparing the genetic profiles of people undergoing primary HIV infection ( in their first year of infection) to those repeatedly exposed to HIV but non-infected. The group of exposed but non-infected patients came from a cohort studied by Dr. Julie Bruneau of the Centre hospitalier de l'Université de Montréal. The cohort of primary HIV infected patients is studied by Dr. Jean-Pierre Routy, from the MUHC. Analyses show that the "good" versions of both genes were present in 12.2% of exposed but non-infected subjects versus only 2.7% in patients in primary HIV infection.

As of yet, no study has clearly described the mechanism of this protection. The KIR3DL1 gene codes for a receptor on the surface of the immune system's natural killer (NK) cells, which when activated destroy infected cells in the body. The HLA-B*57 gene codes for a protein normally found on the surface of all body cells that binds the KIR3DL1 and dampens NK cell activity. The most likely hypothesis is that HIV prevents the HLA-B*57-encoded protein from being expressed on the surface of the infected cells, making it unavailable to bind KIR3DL1. As a consequence, the NK cells retain their activity and destroy the virus-infected cells.

As this mechanism can occur very soon after the virus has started to infect the body cells, people carrying those versions of the 2 genes may be able to destroy more efficiently the infected cells following exposure to HIV, thus lowering their chances of developing AIDS.

"More research is needed to determine the exact mechanism behind the protection we have observed, but these findings have revealed a promising avenue," according to Dr. Bernard.

This study opens the way for new ideas in the fight against HIV infection. "In the future, our findings could be used to somehow 'boost' the innate immune system and thus fight the virus as soon as it enters the body," said Dr. Bernard.

Source: McGill University Health Centre

Explore further: Research exploring common biology of cancer, infection and psychiatric disease

Related Stories

Research exploring common biology of cancer, infection and psychiatric disease

November 16, 2017
Nevan Krogan, PhD, is a mapmaker, but the object of his exploration is not any newfound continent or alien world. Instead, he and his colleagues map cells. Rather than cities, towns and interstates, these maps show proteins, ...

Developing a new vaccination strategy against AIDS

November 16, 2017
According to the WHO, there are currently more than 36 million people infected with the human immunodeficiency virus (HIV) and a further 2.4 million become infected every year. Despite treatment success against the virus, ...

Unique approach to treatment of rare and aggressive blood cancers

November 14, 2017
A unique approach to targeting the abnormal T-cells that cause T-cell lymphomas could offer hope to patients with the aggressive and difficult-to-treat family of cancers, finds a study involving researchers from Cardiff University.

New model may provide insights on neurocognitive disorders caused by HIV

November 8, 2017
HIV infects certain cells in the brain called microglia, and infected microglia release toxic and inflammatory molecules that can impair or kill surrounding neurons. Researchers have been limited in their ability to study ...

New molecule shows promise in HIV vaccine design

October 27, 2017
Researchers at the University of Maryland and Duke University have designed a novel protein-sugar vaccine candidate that, in an animal model, stimulated an immune response against sugars that form a protective shield around ...

Scratching the surface of mature monocytes... and coming up with CXCR7

November 3, 2017
New research published online in the Journal of Leukocyte Biology showed for the first time that mature monocytes (a specific type of white blood cell) express the CXCR7 receptor on their surface. This receptor may be a therapeutic ...

Recommended for you

Scientists find where HIV 'hides' to evade detection by the immune system

October 19, 2017
In a decades-long game of hide and seek, scientists from Sydney's Westmead Institute for Medical Research have confirmed for the very first time the specific immune memory T-cells where infectious HIV 'hides' in the human ...

National roll-out of PrEP HIV prevention drug would be cost-effective

October 18, 2017
Providing pre-exposure prophylaxis (PrEP) medication to men who have sex with men who are at high risk of HIV infection (equivalent to less than 5% of men who have sex with men at any point in time) in England would be cost-effective, ...

Regulatory T cells harbor HIV/SIV virus during antiviral drug treatment

October 17, 2017
Scientists at Yerkes National Primate Research Center, Emory University have identified an additional part of the HIV reservoir, immune cells that survive and harbor the virus despite long-term treatment with antiviral drugs.

New research opens the door to 'functional cure' for HIV

October 17, 2017
In findings that open the door to a completely different approach to curing HIV infections, scientists from the Florida campus of The Scripps Research Institute (TSRI) have for the first time shown that a novel compound effectively ...

Researchers create molecule that could 'kick and kill' HIV

October 5, 2017
Current anti-AIDS drugs are highly effective at making HIV undetectable and allowing people with the virus to live longer, healthier lives. The treatments, a class of medications called antiretroviral therapy, also greatly ...

A sixth of new HIV patients in Europe 50 or older: study

September 27, 2017
People aged 50 and older comprise a growing percentage of HIV patients in Europe, accounting for one in six new cases in 2015, researchers said Wednesday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.