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BY OUR PHARMA CORRESPONDENT
8 September, 2005: There exists an innate defense system present in some patients who remain healthy after years of infection with HIV despite receiving no treatment.
According to an article published in the September edition of the Journal of Virology, the subset of HIV-infected patients referred to as long-term survivors or nonprogressors have higher amounts of a key enzyme in their white blood cells.
Researchers have been trying for years to understand why a small per cent of (nearly 5 per cent) patients with human immunodeficiency virus, do not develop AIDS, or do so very slowly. But some research done in the previous years suggested that such patients maintain higher levels of an enzyme in white blood cells called APOBEC-3G (A3G), and the new study confirmed it in the first experiments on human cells.
A3G "edits," or introduces changes in, the HIV genetic code every time the virus copies itself. By doing so, A3G corrupts the HIV gene code and prevents the virus from reproducing, researchers at the University of Rochester Medical Center reported. Unfortunately, HIV has evolved to counter A3G with viral infectivity factor (Vif), a protein that "grabs" A3G and tricks the body into destroying it. With the "editing enzyme" gone, HIV is free to overwhelm the immune system, leaving patients vulnerable to AIDS infections that take three million lives per year.
BY OUR PHARMA CORRESPONDENT
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