A genetically engineered strain of HIV will allow scientists to study a human version of the disease in monkeys.
Until now, AIDS researchers used monkeys infected with simian immunodeficiency virus, or SIV. The virus is similar to ours, but it's far from a perfect research tool.
"The lack of a primate model that utilizes HIV-1" — the strain that causes human AIDS — "is an impediment to research," write researchers led by Paul Bieniasz and Theodora Hatziioannou of the Aaron Diamond AIDS Research Center.
The new HIV strain, described Monday in* the Proceedings of the National Academy of Sciences*, could eventually make it easier to test drugs and vaccines for the incurable virus.
Though SIV and HIV wreak similar havoc on their hosts' immune systems, drugs affect them differently. While that makes SIV useful for studying how the disease progresses, it's less useful for studying potential treatments. It's impossible to quantify how much this has slowed the search for cures to a disease that kills nearly three million people every year, but it certainly hasn't helped.
Carolyn Williamson, principal investigator of the South African AIDS
Vaccine Initiative, said that existing monkey models are "not ideal"
for testing vaccines and drugs. She was not involved in the study.
"This model is a real step forward in HIV research," said Williamson.
Monkey immune systems normally beat back HIV with the help of two cellular proteins that prevent retroviruses from replicating.
Pigtail macaques, however, lack a gene variant that codes for one of those proteins. By swapping a key gene from SIV into HIV, the researchers produced a strain that evaded the other protein defense.
When the macaques were infected with the engineered HIV, the virus developed slowly, at rates comparable to humans who keep the disease at bay for decades.
"If your drug was developed for HIV-1, it doesn't necessarily work for monkey viruses," said Hatziioannou. "In this model, you know it's going to work the same way as in humans."
Researchers will be able to study the mechanisms of so-called long-term non-progression — and that's just the start. The next step, said
Bieniasz, is the development of an HIV strain that produces full-blown
AIDS in the macaques, allowing researchers to test treatments for that stage of the disease.
*
Citation: "A macaque model of HIV-1 infection." Theodora Hatziioannnou,
Zandrea Ambrose, Nancy P.Y. Chung, Michael Piatak, Jr., Fang Yuan,
Charles M. Trubey, Vicky Coalter, Rebecca Kiser, Doug Schneider, Jeremy
Smedley, Rhonda Pung, Mercy Gathuka, Jacob D. Estes, Ronald S. Veazey,
Vineet N. KewalRamani, Jeffrey D. Lifson, and Paul D. Bieniasz.
Proceedings of the National Academy of Sciences, Vol. 106, No. 9.*
*Image: Names Project Wien / Flickr/zorro-art
*
See Also:
- HIV Evolution Outpaces Vaccines
- Endangered Lemurs Survived Ancient AIDS Epidemic
- Gene Editing Could Make Anyone Immune to AIDS
- Cellular 'Bullets' Destroy HIV, Raise Vaccine Possibilities
- Genes Don't Explain African AIDS Epidemic
- Parasites May Fuel AIDS Epidemic
- Did Merck Bring AIDS to America? No.
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