JAN 04, 2018 5:59 AM PST

How A West African Monkey Avoids AIDS

WRITTEN BY: Kara Marker

How does a West African monkey species called sooty mangabeys resist SIV, the “monkey version” of HIV, and prevent the infection from developing into AIDS? In a novel study comparing the genomes of humans and monkeys, scientists from the Yerkes National Primate Research Center at Emory University make two discoveries that could change the approach to HIV and AIDS.

A sooty mangabey. Credit: Yerkes National Primate Research Center, Emory University

“Sooty mangabeys and other natural hosts have for years served scientists as a roadmap to AIDS therapies, but we've only been able to look at small pieces of the map at a time,” explained co-author of the new Nature study Steve Bosinger, PhD. “Now, by examining the entire genome of these species, our team believes we can accelerate discoveries that make a difference in the fight against HIV and AIDS.”

Sooty mangabeys, known for their brown-gray color, are usually found on the west coast of Africa from Senegal to Ghana. They are natural hosts for SIV, as are drills and African green monkeys. SIV infection in these species is similar to the way HIV infections humans, except immune cell levels do not dwindle to dangerous levels and the infection does not eventually transition into AIDS. Other monkey species, such as rhesus macaques, are not so lucky. As non-natural hosts for SIV, their response to SIV is more like the human response to HIV: lethal.

In the new study, researchers sequenced the sooty mangabey genome and compared it to both human genome sequences and genome sequences of nonhuman primates. Scientists hope that an analysis of the results will help improve therapy for humans with HIV, reduce transmission of HIV from mother to infant, and boost efforts to develop effective HIV vaccines.

"We are taking advantage of an evolutionary experiment that took place over many thousands of years, revealing how it is possible to be infected with SIV and not progress to AIDS," explained study leader Guido Silvestri, MD.

What researchers found from the inter-species genome analysis is two unique changes in immune proteins in the sooty mangabey genome, thought to be two big clues as to how these monkeys deal peacefully with SIV without ever experiencing the lethal grip of AIDS.

The first change was a gene deletion not found in other primates, which resulted in a protein called ICAM2, an adhesion molecule on immune cells, to not function. The second was an alteration of the TLR4 protein, leading to dysfunction. TLR4 proteins are active in the innate immune system, sensing and responding to certain parts of bacterial membranes. Like the ICAM2 deletion, the TLR4 alteration was not found in non-natural primate hosts for SIV.

“Damage to intestinal barriers and bacterial release contributes to chronic immune activation, which is associated with AIDS progression in HIV-infected humans and SIV-infected non-natural hosts,” Silvestri explained.

In the future, Silvestri and others plan on researching more details on the differences between the genomes of sooty mangabeys and other monkeys, as well as more studies with ICAM2 and TLR4 to understand in more detail how they “protect” sooty mangabeys from AIDS.

Sources: National Primate Research Center, Emory Health Sciences

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
NOV 11, 2021
Immunology
Malaria Researchers Make a Surprising Antibody Find
NOV 11, 2021
Malaria Researchers Make a Surprising Antibody Find
Researchers looking into the immunology of malaria infections have made an unexpected find that could ultimately lead to ...
NOV 22, 2021
Plants & Animals
The Lungfish is a Living Antimicrobial Sponge
NOV 22, 2021
The Lungfish is a Living Antimicrobial Sponge
African lungfish are incredible animals that survive in freshwater or on land. Research on lungfish has taught us more a ...
DEC 07, 2021
Immunology
Ancient Medicine and Synthetic Biology Collide to Combat Chemo Resistance
DEC 07, 2021
Ancient Medicine and Synthetic Biology Collide to Combat Chemo Resistance
  Strong chemical drugs used to obliterate all rapidly growing cells in the body have been used to treat cancer sin ...
DEC 09, 2021
Immunology
Stopping the Spread of COVID by Chewing Gum?
DEC 09, 2021
Stopping the Spread of COVID by Chewing Gum?
Scientists have developed a special chewing gum that could reduce the risk of spreading SARS-CoV-2. The technology was d ...
DEC 11, 2021
Health & Medicine
Third Dose of Pfizer-BioNTech Vaccine Could Reduce Effects of Omicron
DEC 11, 2021
Third Dose of Pfizer-BioNTech Vaccine Could Reduce Effects of Omicron
Many mainstream media sources are reporting on a new press release from Pfizer that suggests that a third dose of the Pf ...
DEC 23, 2021
Immunology
Hitting the Anti-inflammatory Bullseye to Treat IBD
DEC 23, 2021
Hitting the Anti-inflammatory Bullseye to Treat IBD
Fifty percent—that’s the percentage of patients with inflammatory bowel disease (IBD) who experience long-te ...
Loading Comments...