In the late ’80s and early ‘90s, HIV/AIDS was a scourge with unknown origins, taking the lives of thousands by the day and spreading fear as fast and wide as the virus itself.
Since then, medical scientists have learned a lot about HIV, so much so that what was once a death sentence now has millions with HIV living healthy and productive lives.
Now, researchers say we could be on the brink of eradicating this deadly virus entirely!
The discovery comes from the fact that there is a small percentage of patients diagnosed with HIV who are able to eradicate the virus within their own body without antiretroviral medications or even stem cell transplants. Somehow these people possess some kind of innate “superhuman” ability to naturally suppress the virus and achieve a medically verifiable cure.
Scientists call this small population “elite controllers,” a name that reflects their unique ability to keep one of the most notorious viruses at bay.
Two of these patients have gained fame in the scientific literature in recent months, each known mostly by a code name — the “San Francisco Patient” and another called the “Esperanza Patient.” Both are women who have been spotlighted in medical journals and at scientific conferences for seeming to have miraculously eradicated HIV from their bodies.
But rather than treating their cures as some kind of divine intervention, researchers want to track down a scientific reason for it, and hopefully one that can be repeated in a potential treatment for all of those infected with HIV.
Beyond those two celebrated examples, new research from the Ragon Institute in Boston has zeroed in on a larger group of elite controllers—58 altogether—who have also been able to keep the virus at bay by virtue of their distinct biological capabilities.
Writing in Science Translational Medicine, immunologists at the institute report that they have uncovered a deep well of new clues that point to elite controllers’ unusual ability to eradicate the virus. One reason is a powerful immune response, but another centers on where latent viral genetic sequences are stranded in the human genome.
In all HIV patients, the virus insidiously inserts itself into the host’s DNA. Unlike other viruses that replicate themselves and therefore the copies are easily identified and attacked by the cells of the immune system, HIV acts like undercover spies. Once it becomes entwined in the host’s DNA, it replicates as the host’s cells replicate, and so it goes unrecognized by the immune system while also suppressing the immune system as a whole.
However, somehow in the elite controllers, their bodies are able to isolate the HIV sequences into remote regions of their chromosome where they’re less likely to replicate and also more likely to be found by immune forces.
Elite Controllers Have a More Effective Immune Response to HIV
The research is opening a new window of understanding into what it means to be infected with HIV, a virus that is estimated to affect 38 million people globally. Millions worldwide have died since the HIV pandemic began 40 years ago.
Most patients take antiretroviral drugs for life to hold the virus in check, but elite controllers can readily subdue HIV for long periods without the need for medications.
“Increasing evidence suggests that durable drug-free control of HIV-1 replication is enabled by effective cellular immune responses,” lead author Dr. Xiaodong Lian wrote of the elite controllers in their study.
The results of the Boston-based team’s experiments suggest that human immunodeficiency viruses such as HIV in elite controllers face greater pressure from more powerful and more targeted immune system cells. As a result, the viruses are unable to dodge the immune system’s formidable army.
Researchers have long known that the human immune system is capable of incredible feats of defense against most pathogens. But it is the ability of HIV and related viruses to virtually destroy those powers that make them so deadly. That is why to date, the best treatments we have developed for HIV/AIDS patients are antiretroviral drugs that work by stopping the virus from replicating. However, these therapies do nothing to boost or reactivate the body’s immune response. This is why currently, patients need to stay on such antiviral therapies for the rest of their lives to survive.
The Boston team and other researchers worldwide are hoping that if they can isolate what it is, that makes the immune system of the elite controllers so much better at combating the virus, they can replicate that effect in “ordinary” HIV patients.
All of the new findings are helping to peel away some of the mystery underlying the phenomenon of elite control. The Ragon Institute reported in the journal Nature last year that the San Francisco Patient, an elite controller, had no intact HIV sequences in her genome. She is completely HIV-free.
Based on the Ragon Institute’s research, this suggests the San Francisco Patient’s immune system may have completely eliminated the woman’s HIV reservoir that normally gets embedded in the DNA of HIV patients. Scientists refer to this rare occurrence as a “sterilizing cure.”
Like the San Francisco Patient, the Esperanza Patient, an elite controller from Argentina, had no intact HIV viruses when scientists studied an astounding 1.19 billion blood cells and 500 million tissue-related cells. A report on her case was published last month by Ragon Institute scientists in the Annals of Internal Medicine.
All of the findings suggest there ultimately may be an “actionable path to a sterilizing cure” for patients who are unable to do this on their own, institute scientists said, but of course adding that “much more work needs to be done.”
