Genetic Variations Might Be Causing Mutations To HIV
Geneticvariations that might help people newly diagnosed with HIV control their viralloads also could be causing a mutation in the virus that makes it less potent,according to a study published Friday in PLoS Pathogens, Reuters reports.
Some people have versions of an immune system gene, called HLA, that are"known to force HIV to tolerate mutations that damage its ability toreproduce," according to Carolyn Williamson of the Centre for the AIDS Programme of Research in South Africa and colleagues. The weakened virusalso means lower viral loads and slower disease progression in people withbeneficial versions of HLA, according to Reuters. The researchersfound that the weakened virus might be transmitted to and act in the same wayin other people, even if they do not have the HLA variation, Williamson said.
The researchers followed 21 women in South Africa who recently contracteda weakened strain of HIV. The women did not have the beneficial HLA variation,according to Reuters. The researchers followed the women forbetween one to three years, Reuters reports. The researchers foundthe women had much lower viral loads, compared with people carrying a strain ofHIV that had not mutated to a weakened state. The researchers also found thatwhile the women's viral loads decreased, their CD4+ T cell counts increased. "Itis pretty well established if you have certain HLA genes, you are betteroff," Williamson said, adding, "It is very likely that the virus inthe people who did not have the HLA gene came from individuals who did."
According to Williamson, the "significant difference to other studies isthat this is showing the actual benefit is due to the genetic composition ofthe virus." She added that the findings show "a survival advantagewith a virus containing specific genetic signatures associated with lowerreplication."
The researchers have not studied the women to see how much slower they progressto AIDS but noted the findings could help researchers looking for an effectivevaccine through an improved understanding of why some people living with thevirus survive longer (Kahn, Reuters, 3/20).
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