With one confirmed exception – the Berlin patient – no one has been cured of HIV. It is possible to nullify the symptoms of the virus, however, and there have also been several cases where levels of the virus in the blood have been essentially undetectable – meaning that the patient can’t pass on the infection to another person.
Although not a definitive cure, this type of viral drawdown can be described as a “functional cure.” Now it seems that scientists from the Florida campus of The Scripps Research Institute (TSRI) may have just found another way to obtain one.
Writing in the journal Cell Reports, they explain how a new type of drug appears to suppress the virus’ replication in chronically infected cells. This prevents viral rebound – wherein the levels of virus in a patient shoot up after an initial slump – even during treatment interruptions.
This has been described by the team as a “Block-and-Lock” approach, in that the reactivation of the virus within cells is prevented and HIV in the patient enters a latent state, doing no harm to the body.
“When combining this drug with the standard cocktail of anti-retrovirals used to suppress infection in humanized mouse models of HIV-1 infection, our study found a drastic reduction in virus RNA present,” TSRI Associate Professor Susana Valente, the coordinating author of the study, said in a statement.
“No other anti-retroviral used in the clinic today is able to completely suppress viral production in infected cells in vivo,” she added.
In the mice tested, they were shown not to experience a viral rebound for up to 19 days after they stopped receiving doses of the compound. In half of all treated mice, the virus was undetectable for 16 days after the treatment stopped. Imagine if the same effect could be reproduced in HIV-positive people.
The focus of the research was a compound named didehydro-Cortistatin A, or dCA for short. First isolated from the marine sponge Corticum simplex back in 2006, a researcher at TSRI managed to synthesize it in a laboratory just two years later.
The TSRI team have been working with it for some time now, and in 2015 announced that it has HIV-disrupting characteristics. This new study confirms that it blocks Tat, a regulatory protein that boosts the rate in which HIV copies DNA into RNA – a vital process in its life cycle.
“It is really the proof-of-concept for a ‘functional cure,’” Valente explained. She also pointed out that the maximum dose of the drug had “virtually no side effects.”
Again, this was only tested on mice at this stage, but this is standard procedure for these types of trials. It's currently unknown as to how effective this will be in humans, but results like this are extremely promising.
HIV/AIDS used to be a life-destroying disease. Now people can not only live normal lives with it, but they can see how science is paving the way to both functional, and complete, cures.