Scientists Cured HIV in Mice. They Say a Human Cure Could Be Next.
Scientists used gene-editing technology to cure the mice.
Close to 37 million people living with HIV could be impacted by a new study published in Nature Communications earlier this week.
Scientists found that the HIV virus can be completely eradicated in some infected mice by using a gene-editing technology, called CRISPR, and a slow-release virus suppression drug. The positive results were achieved by two teams of specialists — which included virologists, immunologists, molecular biologists, pharmacologists and pharmaceutical experts — led by Kamel Khalili from Lewis Katz School of Medicine at Temple University and Howard Gendelman from the University of Nebraska Medical Center.
“We think this study is a major breakthrough because it for the first time demonstrates after 40 years of the AIDS epidemic that the HIV disease is a curable disease,” said Khalili, chair of the department of neuroscience and director of the Center for Neurovirology and the Comprehensive NeuroAIDS Center.
HIV, or human immunodeficiency virus, is a disease that targets human T cells, which are responsible for fighting off infections, bacteria, parasites, and other antigens. The virus is spread through contact with certain bodily fluids of an infected person, and without treatment, HIV can develop into AIDS, which severely weakens and even destroys the human immune system to the point of being unable to fight off infections. This later stage of the virus is what has claimed millions of lives since the epidemic was declared.
However, today, with effective treatment, people with HIV can lead healthy lives. They can even reduce the levels of the virus in their body to undetectable levels at which point they are also unable to transmit the virus to others.
An effective cure for human HIV infection has yet to be found, but the team of scientists have brought the world one step closer to a solution.
The study was performed on mice that were scientifically manipulated to produce human T cells that were vulnerable to HIV infection. Before the joint study begun, Gendelman had been conducting trials for LASER ART — also known as long-acting, slow-effective release antiretroviral therapy — while Khalili spent five years experimenting with CRISPR. The study combined their independent research.
The team first used Gendelman’s LASER ART to prevent the replication of the virus’s cells, manipulating the drug to focus on locations in the body where HIV cells were likely to develop like in spleen, bone marrow, and brain tissue. They then used the gene-editing tool to wipe the HIV chromosome from the mice DNA. After years of examining tissue where infected cells could have been hiding in the mice, the scientists were able to confirm that the process was succesful in fully eliminating the HIV virus in nine of the 23 mice used in the study.
However, Khalili, Gendelman, and their team are clear that while this is just a step in the right direction, it is ot evidence of a complete cure for humans.
“Things that work in mice, may not work in men,” Gendelman said. “The limitations of any mouse work have to do with the species, how the drug is administered, the distribution, which is a lot easier than a man or a woman.”
The team is now looking to replicate this study in other species to take their research forward.
“We now have a clear path to move ahead to trials in non-human primates and possibly clinical trials in human patients within the year,” Khalili said in a press release.
Khalili also explained that there would need to be an increase in the effeciency and safety of their method before they can move forward. The team remains hopeful their method will work in their current study on primates. The effectiveness of their method in the primate study will take nine months to a year to corroborate.
If the study yields positive findings, the first phase of clinical human trials could be approved by the Food and Drug Administration as early as the summer of 2020. However, other experts like Kevin Morris, a professor at the Centre for Gene Therapy at City of Hope, have serious concerns about the side effects of this type of treatment in humans, despite being elated by the discovery.
“[It] has the risk of causing cancer,” he said. “This is because the approach depends on using a gene therapy that is known to persist a long time in the body. The long-term persistence could lead to CRISPR — which cuts HIV out of the cell — cutting other sites in an uncontrolled manner. The cutting of other sites in the human cell could lead that cell to become cancerous.”
There are other methods of curing HIV that continue to be tested, like a vaccine that was found to be safe and saw evidence of an immune response in humans and rhesus monkeys. Researchers say they have also been able to cure two HIV-positive people by transplanting stem cells donated by individuals with a highly uncommon genetic mutation that makes them resistant to the virus.
While the impact may not be immediate, it is clear that there is progress being made on a number of fronts in developing a cure for HIV. If and when it is achieved, it will be life-changing for the global human population that has constantly battled the virus since it claimed epidemic status in the 1980s.
“We are at the cusp of a scientific revolution in human genomes that can change the course, quality and longevity of life,” Gendelman said.