Spanish researchers from the IrsiCaixa AIDS Research Institute have discovered themolecule responsible for the entry of the HIV virus into dendritic cells, belonging to the immune system, which contribute to the spread of the virus in the body. The finding, published inPLoS Biology, opens the doors to a new family of AIDS drugscapable of blocking this molecule and thus avoiding the resistance to therapy that current treatments entail.
According to the SINC agency, the results reveal the existence of molecules on the surface of HIV, essentially constituted by a sialic acid linked to a sugar, which in turn is anchored to a lipid, and which are calledgangliosides. These types of molecules are found in high concentration in the membranes of nerve cells and, to a lesser extent, in the membranes of other cells, and HIV selectively captures these molecules during its replication process within an infected cell.
Scientists have altered the ganglioside composition on the surface of man-made viruses and liposomes (spherical vesicles formed by the components of cell membranes). By putting these particles in contact with dendritic cells, they showed that only those vesicles with specific gangliosides on their surface could enter the cells. Finally, the researchers concluded that removing the gangliosides from the AIDS virus prevents dendritic cells from trapping HIV-1, internalizing it, and facilitating the infection of its natural targets, CD4 T lymphocytes. According to Nuria Izquierdo, a researcher at IrsiCaixa, “this has shown thatgangliosides are the key to the entry of HIV into these cellsand that its entry mechanism does not depend on the proteins of the virus, but mainly on the presence of these molecules “.
If a pathogen enters the body, dendritic cells play a key role in activating the immune response. Its function is to patrol the body, capture infectious agents that invade it, isolate their molecules and present them to T lymphocytes, cells in charge of specifically destroying microbes and cells already infected. However, HIV takes advantage of dendritic cells to take refuge inside them without actually infecting them and thus being able to reach its main targets, the CD4 T lymphocytes. Thus,dendritic cells act like true “Trojan horses”, since they concentrate the virus in the area of contact with CD4 T lymphocytes, favoring their infection instead of initiating an adequate immune response against HIV.
This discovery provides new clues about how HIV enters dendritic cells, escapes the usual path of pathogen degradation, and creates an ideal setting for new cell infection and disease progression.
