Different combinations of genetic variants of two modulators of the innate human immune system strongly influence AIDS progression in HIV-positive individuals, according to a study to be published online in Nature Genetics.
Natural killer cells are part of the antiviral immune response, and their activity is controlled by receptors called KIRs that are present on the cell surface. The KIR receptors that inhibit natural killer cell activity (KIR3DL1) are triggered by HLA-B molecules, which are presented by other cells of the immune system. Mary Carrington and colleagues examined variation in the genes encoding KIR3DL1 and HLA-B in more than 1,500 HIV-positive individuals, and found that particular combinations of variants conferred protection against AIDS progression.
These results may explain at least part of the variability in progression of the disease in infected individuals. The authors also note that the observed rapid evolution of these genes may be driven by pathogens such as HIV.
Mary Carrington (National Cancer Institute, Frederick, MD, USA)
Abstract available online.
(C) Nature Genetics press release.
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