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A new international collaborative project is to search for key genetic variants that determine indviduals’ response to infection by HIV, human immunodeficiency virus. Researchers at Duke University in the US will lead a consortium of American, European and Australian scientists, supported by the Center for HIV/AIDS Vaccine Immunology (CHAVI). The EuroCHAVI project will recruit 600 patients from nine cohorts and seek to identify common genes that affect immune responses to HIV using advanced technologies for genetic analysis. By identifying links between certain types of response and specific haplotypes, key genetic variants involved in these responses may be distinguished. This project is an undertaking made possible by the creation of the human haplotype map or HapMap, a catalogue of sets of single nucleotide polymorphisms (SNPs) representing key sites of genetic variation between human individuals.

Individuals exposed to HIV show considerable variation in terms of the immune response mounted against the virus, which affects the timing and progression to AIDS. A minority show a high degree of resistance to infection, and a few genetic variants (such as the CCR5 delta32 mutation) have been identified that confer some measure of innate resistance. By studying the nature of different responses to HIV and the genetic factors underlying this variation, researchers hope to find a way of creating a vaccine that would stimulate appropriate, protective immune responses against the virus. CHAVI also plans to extend the same genetic analyses used in the EuroCHAVI project to a larger, African cohort of HIV-infected patients.

Director of CHAVI's host genetics research core David Goldstein said: "We intend to use natural genetic differences among people to point the way toward the most promising avenues for vaccine development", adding that: "the prospects are very real for getting answers by next year" (see press release). Director of the Duke Institute for Genome Sciences & Policy Huntingdon Willard commented: "Large-scale genome analyses like this are critical for determining the role of the genome in complex diseases such as AIDS…The combination of large population cohorts and state-of-the-art genome technology will allow us to dissect the genetic factors that contribute to disease".