Just a few decades ago, a diagnosis of human immunodeficiency virus (HIV) meant a death sentence. Today, thanks to the development of antiretroviral (ARV) drugs, most people can manage their HIV symptoms and live long lives. Sadly, despite additional advancements in medical science, there is still no cure for HIV or acquired immunodeficiency syndrome (AIDS).
Recently, scientists and experts in the field of virology gathered for the 2019 Conference on Retroviruses and Opportunistic Infection (CROI). The most notable presentations at this year’s CROI involved the treatment of HIV.
However, one new treatment breakthrough was met with controversy because it involves the use of clustered regularly interspaced short palindromic repeat (CRISPR) gene editing.
Repliclones May Be the Key
For years, scientists have struggled with the fact that antiviral therapy is ineffective for around 10 percent of HIV patients. When ARV drugs don’t work, frustration mounts. Doctors order extra tests, change regiments, and unintentionally create new side effects for their patients.
At CROI 2019, University of Philadelphia scientists presented a study attributing this phenomenon to repliclones, replicating cells that conceal the HIV genome within themselves. Because repliclones don’t respond to standard antiviral therapy, some patients using ARV drugs don’t experience a decrease in viral load. Researchers hope this new discovery can provide peace of mind for doctors and patients regarding the strange phenomenon.
However, retrovirus specialists hope this breakthrough leads to more than just greater understanding. According to George Pavlakis, a retrovirologist at the National Cancer Institute, the repliclones discovery may lead to an HIV cure using gene editing. “It’s a science fiction idea that one day may be possible.”
Gene Editing Cures Monkey HIV
First, the researchers engineered a viral shell capable of seeking out SIV-infected gene sequences. Then, they paired it with a CRISPR enzyme capable editing SIV out of healthy tissue and injected the mixture into the monkeys’ bloodstream. Following the treatments, the team detected no SIV virus in the blood of the test subjects who received CRISPR treatment.
Additionally, the Temple University team discovered CRISPR protein in 14 tissue samples, proving the enzyme spread throughout the monkeys’ entire bodies.
CRISPR May Not Be Ready for Human Testing
Despite the results of the Temple University study, some experts believe current gene editing technology may not be up to par. Dr. Pavlakis argues that the risk of CRISPR enzymes making cuts in the wrong cells is simply too high. Especially since scientists have a hard time directing fabricated enzymes to attack infected cells. “CRISPR right now is not there,” stated Pavlakis.
Even so, Philadelphia biotech company Excision BioTherapeutics is seeking approval to launch clinical trials of CRISPR treatment in humans by the end of 2019.
While the technology may not be at the necessary level yet, this research is promising. For the sake of the 36.9 million people living with HIV, every potential treatment must be explored. Considering the success of CRISPR so far, a cure for HIV and AIDS seems closer than ever.