Review: A new discovery around HIV

Review: A new discovery around HIV

Title of the article: “Gene Variation May Rise Risk of HIV”
Source: The New York Times.
http://www.nytimes.com/2008/07/17/science/17hiv.html?_r=1&oref=slogin
Date of Publication: July 17, 2008
Author: NICHOLAS WADE

Garcia Fernandez, Gabriela.

This review is based on an article by Nicholas Wade from the New York Times, which explains the new conclusions reached by scientists in relation to HIV/AIDS. The article is based on a new discovery around the HIV virus found by a group of researchers from Texas and London. The discovery is expected to offer an important insight into the biology of the virus.
According to the article, a genetic variation that once protected people in sub-Saharan Africa from a now extinct form of Malaria may have left them more vulnerable to HIV. This would explain why AIDS is more common there than expected. The genetic variation has been studied in the US, where African-Americans who carried the variation were 50% more likely to acquire HIV than African-Americans who did not.
The geneticist David Goldstein said that “if the new results are comfirmed, it would mean that selection for resistance to Malaria has created a vulnerability to infection with HIV”. The genetic variation involves a change in one unit of DNA. As a consequence of this, red blood cells fail on inserting a certain protein on their surface. This protein is a receptor which receives signals from a hormone known as CCL5, part of the immune system’s regulatory system. The receptor was also used by a Malaria parasite to gain entrance to the red blood cells. More than 90% of people in Africa now lack the receptor on their red blood cells, as do about a 60% of African-Americans.
The Texas-London research team is not certain how lack of the receptor promotes HIV infection, but Dr. Ahuja, who wrote the report, said that “the blood cells act like a sponge for the hormone CCL5”. Because CCL5 is known to obstruct multiplications of the virus, having lots of the hormone in the bloodstream may prevent the infection. Conversely, people whose blood cannot soak up the hormone could be more vulnerable.
Dr. Weiss contribution to the research was the fact that the red blood cell receptor was similar to another receptor, the CCR5. This one occurs on the surface of the white blood cells, which are HIV’s mayor target. A small percentage of Europeans have a mutation that prevents CCR5 receptor from being displayed on the surface of white blood cells, and they are protected against HIV. The absence of the two receptors has the opposite effect: vulnerability to HIV, when the red cell receptor is missing, protection from it, when the white cell receptor is withdrawn.
As it’s often the case with provocative new findings, the researchers may have some way to go before convincing others that their observation is correct. From the time being, this new discovery offers a new possibility to the understanding of the virus, and some answers to the questions that arise around this terrible disease.