The AIDS virus is rapidly evolving to recognize and evade human immune systems, making the development of a vaccine even less likely than it already is.
Researchers already knew that HIV adapts on a person-by-person basis, but they didn't know if those changes were passed to the viral population at large. Gene sequencing of HIV samples taken from 2,800 people show that changes have spread throughout the world.
The adaptations involve genes responsible for coding proteins that are recognized by white blood cells. Troublingly, the most rapidly-evolving HIV genes appear to be those used by the human immune system to identify its enemies.
"The virus is out-running human variation," said study co-author Rodney Phillips, an Oxford University immunologist, in a press release.
The findings, published Wednesday in Nature, are the latest setback for the beleaguered field of AIDS vaccine development. Hundreds of millions of dollars have been spent on vaccines, none of which have worked, with the most high-profile vaccine — developed by Merck and the National Institutes of Health — appearing to increase infection risks.
However, though HIV's rapid adaptations may make vaccines — necessarily targeted at a frozen-in-time viral profile — obsolete, it's not necessarily outrunning the evolution of human immune response. That's a small consolation, but consolation nonetheless.
"It could equally be that as the virus changes, different immune responses come into play and are actually more effective," said Philip Goulder, an Oxford University pathologist and study co-author.
Citation: "Adaptation of HIV-1 to human leukocyte antigen class I." By Yuka Kawashima, Katja Pfafferott, John Frater, Philippa Matthews, Rebecca Payne, Marylyn Addo, Hiroyuki Gatanaga, Mamoru Fujiwara, Atsuko Hachiya, Hirokazu Koizumi, Nozomi Kuse, Shinichi Oka, Anna Duda, Andrew Prendergast, Hayley Crawford, Alasdair Leslie, Zabrina Brumme, Chanson Brumme, Todd Allen, Christian Brander, Richard Kaslow, James Tang, Eric Hunter, Susan Allen, Joseph Mulenga, Songee Branch, Tim Roach, Mina John, Simon Mallal, Anthony Ogwu, Roger Shapiro, Julia G. Prado, Sarah Fidler, Jonathan Weber, Oliver G. Pybus, Paul Klenerman, Thumbi Ndung’u, Rodney Phillips, David Heckerman, P. Richard Harrigan, Bruce D. Walker, Masafumi Takiguchi & Philip Goulder. Nature, Vol. 457 No. 7233, Feb. 25, 2009
See Also:
- Endangered Lemurs Survived Ancient AIDS Epidemic
- Gene Editing Could Make Anyone Immune to AIDS
- Cellular 'Bullets' Destroy HIV, Raise Vaccine Possibilities
- Parasites May Fuel AIDS Epidemic
- Genes Don't Explain African AIDS Epidemic
- Trial Begins for HIV Gene Therapy
- Gene Variant Points to Personalized HIV Treatments
Brandon Keim's Twitter stream and Del.icio.us feed; Wired Science on Facebook.
