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For the first time, researchers have been able to uncover the secret of why some people do not develop AIDS despite having an HIV infection. This creates further opportunities for a vaccine.
Researchers are secret to why some people do not get AIDS despite HIV infection. The key, as is so often the case, lies in the genes, but the results of the study also give hope for the development of a vaccine.
HIV controllers do not develop AIDS Not all HIV-infected people develop AIDS because around one in three hundred patients do not develop an immune deficiency disease or the virus is successfully combated by the body's own defenses. Why these so-called HIV controllers do not develop AIDS without medication or treatment despite HIV infection has so far been a mystery to science. However, an international team of researchers has now come to the realization that the reason is in the genes and was able to determine the hereditary system for the first time, which is the basis for successfully fighting the immune deficiency disease through the body's own resistance.
300 gene variants make the difference The international team of researchers led by Florencia Pereyra from the University of Harvard, USA, carried out a comprehensive study to examine the genome of almost 1,000 HIV controllers and 2,600 other HIV patients in detail, and the results of the study were published in the current issue of the scientific journal Science " released. The analysis of the genetic makeup of the controllers showed that they have around 300 gene variants, which the immune system can identify those cells that are infected with the AIDS pathogen, so that a successful fight by the immune system is possible.
Gene variants of the HL antigens crucial The gene variants discovered, so-called single nucleotide polymorphisms, are all located on the area of chromosome 6, which comprises the HL antigens (human leukocyte antigen), the HL antigens of HIV- Controllers were particularly pronounced, according to the scientists. In addition, the HL antigens showed changes in them that are directly related to the production of the HLA proteins. These HLA proteins are proteins that, among other things, bind fragments of viruses to infected cells and present them on the cell surface so that the body's defense can recognize them as intruders. “Previous studies have shown (already) that certain genes are important for HIV control that are related to the HLA system. But they could not show exactly which genes are involved and what causes the differences in the course of the infection, "said co-author Paul de Bakker from Brigham and Women's Hospital as part of the" Science "article.
The HLA-B protein fights the HI virus "Our result not only points to a special protein, but even to a region of the protein that has a decisive influence on its function," said Paul de Bakker. With regard to the successful detection and control of the HI virus, the gene areas for six amino acids, which are required for the formation of the HLA-B protein, are particularly important. HLA-B has a slightly different structure in HIV controllers, with five of the six amino acids located directly at the binding sites that absorb the so-called virus peptides. "The amino acid at the HLA-B binding site influences its shape and structure and is likely to ensure that some peptides are effectively presented and others are not," explained Paul de Bakker in the "Science" article. His research colleague Bruce Walker, head of the Ragon Institute, added: “Of the three billion building blocks in the human genome, only a handful make the difference between those who stay healthy despite HIV infection and those who do not have AIDS get sick. "
Hope for HIV remedies The findings of the researchers could advance science in the search for a remedy for AIDS, according to the unanimous reaction of the experts to the "Science" publication. But "there is still a long way to go before we can convert this knowledge into therapy for patients or the development of a vaccine," emphasized Bruce Walker. At the same time, however, the specialist emphasized that the research "nevertheless went a big step further" with the results. (Fp, 05.11.2010)
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