With more than 36 million people worldwide living with the virus, a permanent HIV cure is yet to be found. However, scientists have just made a breakthrough by finding a way to eliminate the HIV-1 infection in mice.
While there is currently no HIV cure, scientists have just took a huge step closer to finding one. Using a gene editing technology called “CRISPR/Cas9,” the scientists successfully removed the HIV-1 provirus in three animal models.
A provirus is an inactive form of a virus. It occurs when the virus has entered the genes of a cell. In the case of HIV, these host cells are a type of white blood cells called CD4 cells needed to fight infections. Once the virus has become part of the DNA of the CD4 cells, it replicates itself with each new set of CD4 cells produced.
The three mouse models used in the research included a “humanized” model, in which the mice were genetically modified to have human immune cells, which were then infected with HIV-1.
The team was co-led by Dr. Wenhui Hu, Ph.D., associate professor in the Center for Metabolic Disease Research and the Department of Pathology at the Lewis Katz School of Medicine (LKSOM) at Temple University in Philadelphia, together with Kamel Khalili, Ph.D., Laura H. Carnell Professor and chair of the Department of Neuroscience at LKSOM, and Won-Bin Young, Ph.D, who just recently joined LKSOM.
The new study – published in the journal Molecular Therapy – builds on previous research by the same team, during which they used genetically modified rodents to demonstrate that their gene editing technology could eliminate the HIV-1-infected segments of DNA.
Gene editing strategy nearly 100% effective
The team inactivated the HIV-1, reducing the RNA expression of viral genes in the organs and tissues of genetically modified mice by up to 95 percent.
The researchers then tested their findings by acutely infecting mice with EcoHIV – the equivalent of the HIV-1 in humans. The method was up to 96 percent effective in removing EcoHIV in mice.
Finally, in the third model, mice received a transplant of human immune cells, including T cells, which were then infected with HIV-1. The virus’s ability to “hide” in the genes of T cells is one of the main reasons a HIV cure has been elusive.
After just a single round of gene editing therapy, the viruses were eliminated from the human cells that had been attached to the mouse tissues and organs. They removed the provirus from the mice’s spleen, lungs, heart, colon, and brain after only one therapy injection.
Findings bring scientists closer to an HIV cure
This is the first time that scientists have managed to halt the replication of the HIV-1 virus and eradicate it completely from infected cells in animals.
The research also provided the first real evidence that HIV-1 can be successfully eliminated, and full infection with the virus prevented.
“The next stage would be to repeat the study in primates, a more suitable animal model where HIV infection induces disease, in order to further demonstrate elimination of HIV-1 DNA in latently infected T cells and other sanctuary sites for HIV-1, including brain cells. Our eventual goal is a clinical trial in human patients.”
Kamel Khalili, Ph.D.