Scientists have been able to "excise" the HIV genome from human immune cells

The human immunodeficiency virus has the ability to integrate its own genome into the DNA of the host cell. Experts have called this life cycle of the virus the provirus stage. As scientists note, it is this ability of the virus that prevents the disease from being cured - by integrating into cellular DNA, the virus becomes resistant to treatment and becomes insensitive to drugs. The virus remains in the body even after the end of the course of therapy. At a certain point, HIV becomes active and begins to multiply, thereby destroying the cell.

It is assumed that in order to completely destroy the virus in the body, it is necessary to eliminate all copies of the viral genome from the DNA of an HIV-infected person. A group of scientists from Temple University in Philadelphia were able to achieve this result. To do this, specialists needed to find the genes of the virus in the cellular DNA. For this purpose, scientists used synthesized ribonucleic acid, which "sticks" to the virus as soon as it detects it in the cell. This ribonucleic acid (guide RNA) reacts only to the genes of the virus, i.e. it does not bind to the cellular genes of the human body.

Scientists made the ribonucleic acid molecule quite short – 20 nucleotides in length, and thanks to the molecule, scientists were able to determine the boundaries of the viral genome in DNA. In other words, the ribonucleic acid molecule not only reveals the presence of the virus in the DNA structure, but also its beginning and end in the chain.

Once the virus has been identified, it must be removed. For this purpose, a ribonucleic acid guide molecule is also used, which delivers the Cas9 nuclease enzyme to the modified cell. Currently, such an enzyme is actively used by specialists to change DNA in living cells. Under natural conditions, the Cas9 nuclease is part of the antiviral defense. After a series of experiments, specialists determined that the nuclease enzyme can be programmed to cut out any chain in DNA. However, this requires a kind of "guiding instruction", which is the ribonucleic acid molecule. In their work, a group of specialists was able to cut out a certain nucleotide part of HIV, after which the cell's restorative cellular systems were activated, which "glued together" the empty space formed after the removal of the virus genome.

In a paper published in a scientific journal, the researchers noted that they had successfully "cut" the HIV genome from the DNA of immune cells. The research project was the first of its kind, but clinical use of the technique is still some time away.

The experts conducted the experiment in cell culture and are currently considering how to equip every infected cell in the human body with a similar DNA-editing system.

In addition, HIV has an increased ability to mutate, which is also important when developing a ribonucleic acid molecule that will detect altered DNA cells.