HIV immunity Genes?

[madanthonywayne]

Scientists have discovered 2 genes they believe confer resistance, or maybe even immunity, to HIV.

Scientists have isolated two genes which may prevent people from contracting HIV or at least slow the rate at which they develop AIDS, a new study has found.

The genes were isolated by comparing the genetic profiles of people in their first year of HIV infection with those who managed to resist infection despite repeated exposure to the virus.

The "good" versions of the two genes were present in 12.2 percent of those who resisted infection compared with only 2.7 of patients in primary HIV infection.

Researchers are not yet sure how this protection works.

One of the genes codes for a receptor on the surface of the immune system's natural killer cells which destroy infected cells in the body.

The other codes for a protein which binds the first gene and dampens the natural killer cell activity.

The most likely explanation is that HIV prevents the protein that dampens the killer cell activity from being expressed, allowing the killer cells to destroy cells infected with HIV.

Since this can happen very soon after the initial infection, people carrying those genes may be able to more efficiently destroy infected cells and lower their chances of developing AIDS.

"More research is needed to determine the exact mechanism behind the protection we have observed, but these findings have revealed a promising avenue," said co-author Nicole Bernard of the Research Institute of the McGill University Health Centre in Montreal.

"In the future, our findings could be used to somehow 'boost' the innate immune system and thus fight the virus as soon as it enters the body."

The study was published Wednesday in the journal AIDS. http://www.breitbart.com/article.php?id=080717144009.av7fkle4&show_article=1

 

[Hercules Rockefeller]

Here is the journal publication abstract....


A combined genotype of KIR3DL1 high expressing alleles and HLA-B*57 is associated with a reduced risk of HIV infection.
AIDS. 22(12):1487-1491, July 31, 2008.
Boulet, Salix; Kleyman, Marianna; Kim, Jenice YJ; Kamya, Philomena; Sharafi, Saeid; Simic, Nancy; Bruneau, Julie; Routy, Jean-Pierre; Tsoukas, Christos M; Bernard, Nicole F

Abstract:
Objectives: Coexpression of certain combinations of natural killer cell receptor KIR3DL1 and HLA-B alleles is associated with slower time to AIDS. The strongest protection in terms of disease outcome in KIR3DL1 homozygotes (3DL1 hmz) is coexpression of HLA-B*57 and a set of KIR3DL1 genotypes (3DL1*h/*y) lacking alleles expressed at low levels on natural killer cells. We questioned whether this allele combination could also influence resistance to infection.

Design: The genetic distribution of 3DL1*h/*y and HLA-B*57 was compared in 41 HIV-exposed uninfected and 186 recently HIV-infected 3DL1 hmz.

Methods: KIR3DL1 subtyping was performed by sequencing the exons 3, 4, 5, 7-9. The major histocompatibility complex class IB locus was typed by sequence specific oligonucleotide PCR and sequencing to resolve Bw4 and Bw6 alleles and the amino acid present at position 80.

Results: Percentage carriers of HLA-B*57 in HIV-exposed uninfected and individuals in a primary infection cohort was 12.2 and 4.3%, respectively (P = 0.0631), whereas that of 3DL1*h/*y was similar in both populations (P = 0.221). The 3DL1*h/*y-HLA-B*57 combined genotype was more frequent in exposed uninfected individuals (12.2%) than individuals in primary infection (2.7%) (P = 0.019; odds ratio, 5.03; 95% confidence intervals, 1.38-18.3).

Conclusion: Coexpression of 3DL1*h/*y and B*57, which has been associated with a reduced risk of progressing to AIDS in HIV-infected individuals also lowers the risk of HIV infection in exposed uninfected individuals.