Key Points

Scientists at Johns Hopkins University in the US showed that a molecule within HIV can be manipulated and amplified to force the virus into long-term dormancy -- a state in which HIV does not replicate.

The new findings add to a growing body of evidence that may help researchers develop a gene therapy that boosts the production of the molecule -- an "antisense transcript," or AST, said Fabio Romerio, Associate Professor of molecular and comparative pathobiology at the Johns Hopkins University School of Medicine.

The study builds on previous research which showed that AST is produced by HIV's genetic material and is part of a molecular pathway that essentially puts the virus to sleep -- a state known as viral latency.

Worldwide, 39.9 million people are living with HIV, and 630,000 deaths from HIV-related illnesses each year, according to the World Health Organization.

Standard treatment for HIV involves taking daily antiretroviral therapy that stops the virus from making new copies of itself and from spreading. Antiviral medicines must be taken long-term, and they carry short- and long-term side effects, whereas gene therapy would require as little as one dose.

Even after several years of antiretroviral therapy, the virus can remain in cells and tissues throughout the body, quickly spreading if the infected individual stops the therapy, Romerio said.

"Our aim is to find a way to provide a lasting, durable treatment for HIV," said Rui Li, postdoctoral fellow in Romerio's lab and first author of the paper, published in the journal Science Advances.

Romerio noted that the new findings could lead to gene therapies that permanently enhance the production of AST in the T cells of people with HIV, placing the virus in a state of long-term sleep.

To investigate the role of AST in viral dormancy, scientists first turned to a human cell line of CD4+T cells, the immune cells HIV targets to insert its genome and make copies of itself.

The scientists genetically engineered these T cells, infected with HIV, to boost the production of AST by inserting a genetic element capable of generating many copies of AST.

The team also studied AST in CD4+T immune cells collected with permission from 15 people with HIV.

Using a method that can accurately measure whether HIV is asleep or awake, the scientists found that the virus remained dormant in all of the cells for four days. After that, the AST-expressing DNA degraded within the T cells.

- IANS