How far have we gotten in the battle against HIV?
Maria Zagorulya is a student at the University of Rochester and is a journalist for JYI. She is currently pursuing a degree in Biochemistry.
For nearly four decades HIV has been a major public health threat and cause of public anxiety. It is contracted by 35 million people each year, says the World Health Organization, and is the world’s sixth leading cause of death. Despite years of effort and funding, researchers have yet to find a permanent cure for AIDS. What approaches are scientists taking, and what are the obstacles in their way? Are we closer to eradicating the disease?
Like all viruses, HIV sneaks into a cell and turns it into a virus factory. By exploiting the cell’s internal machinery to produce more copies of itself, the virus weakens and kills the cell and spreads the infection. HIV seeks out T-cells, which are a critical part of the body’s defense system against disease-causing pathogens. As the virus weakens the defense system, the body becomes prey to infections caused by all kinds of pathogens, a condition classified as the disease AIDS. People with AIDS die not from HIV itself, but from their lack of protection against other pathogens.
One thing that makes HIV hard to cure is that the virus can form reservoirs in the body where it hides in a dormant state, undetectable by current tests. Even when the body is cleared of active HIV, the latent virus in the reservoirs can emerge and reinfect the patient.
“Latent reservoirs are the chief impediment to curing HIV right now,” said Dr. Jerome Zack, an HIV researcher at UCLA who is exploring one promising approach to the issue. A new study by Zack’s team raises the promise of a novel drug delivery system that could advance the development of HIV treatment.
Current HIV treatment is not a true cure, although it can control the virus and restore patients to good health. It relies on a cocktail of three antiviral drugs that is tailored to each patient. However, the treatment does not delete the latent reservoirs.
“If we can activate the latent virus, essentially turning it on,” Zack said, “we can treat it and eradicate it, thus curing the patient of HIV infection.”
While certain drugs can activate latent HIV, they have serious side effects, and the necessity of their safe and targeted delivery was a major obstacle. In their recent paper in the journal ACSNano, Zack’s research team showed how one of these drugs, bryostatin-1, can be delivered into T-cells inside tiny “vault nanoparticles” that they built in their lab. Vault nanoparticles are a natural part of cells, which makes them a useful vehicle for targeting drugs to specific sites in the body. In learning to engineer vault nanoparticles, Zack and his collaborators are learning to work at the scale of HIV, targeting specifically T-cells.
“I believe that drugs that can activate latent HIV have the potential to be (in combination with other therapies) a cure for AIDS,” said Dr. Leonard Rome, another member of Zack’s team.
Other HIV researchers are working to develop methods of AIDS prevention. Recently, Dr. Scott Blanchard and his team from Weill Cornell Medical College reported a new imaging technique that enables them to observe HIV surface proteins in real time. The new tool allowed them to watch as part of the AIDS virus, the ENV protein, latched onto a target cell. This event is a key stage in viral fusion, the process by which HIV infects T-cells. Better knowledge of the biology of HIV proteins will accelerate HIV prevention research focused on preventing viral fusion.
Blanchard suspects that the technique will lead to a significantly more detailed understanding of HIV activity, which will contribute to the progress in the different strategies of pursuit of an HIV vaccine. “While these pursuits have been difficult to achieve in the case of HIV due to our lack of understanding of the fusion mechanism and the rate at which the virus evolves in patients, it should be possible given sufficient resources and time,” Blanchard said.
Scientists believe that the results of HIV research seem promising, however, it typically takes at least several years for scientific discoveries to be translated into medicines and vaccines.
This feature was developed under the guidance of Science Writing Mentor Andrew Alden.