Entamoeba Histalyticism is a parasitic little known in our latitudes. But in vast areas of the African continent, Central-Meridional America and Asia, where the climate is tropical and the often lacking hygienic conditions, it is a very concrete danger. In fact, this Ameba infected over 50 million people every year, causing almost 70 thousand deaths. In the most serious forms it can invade organs such as the liver and the brain, causing extremely dangerous abscesses. To do this, he uses a unique mechanism, which allows this Ameba to “eat” the cells of our body, and steal pieces to wear as a sort of disguise, and thus escape the attention of the immune system.
A new research by the University of California in Davis takes stock of this ability still not very understood by science, and on the methods with which in the coming years it could be designed to develop new drugs and therapies.
A recent discovery
Although these are a dangerous and extremely widespread parasite, until recently it was known very little of the Histolytica atmosphere. In man it causes annoying diarrhea and colitis, but normally not very dangerous. But also, more rarely, invasive infections, during which it can reach any organ of our body (more frequently happens to the liver and brain), causing abscesses that can prove fatal, if they are not treated promptly.
Its name derives from the ability to “dissolve” the cells, leaving behind their liquefied remains that fill the characteristic abscesses of invasive infections. In the past it was believed to do it by injecting toxins inside the cells. But in 2011, a study carried out by Katherine Ralston – researcher of the University of California in Davis who also participated in the new article published on Trends in parasitology – has identified a completely different mechanism.
A cannibal amnoba
Under the lens of her microscope, the researcher has in fact observed the microscopic Amebe detach pieces of the membrane of the cells of the infected body, killing them, and then ingest them. Subsequently, the works of his team made it possible to understand that the phenomenon is similar to the trogocytosis that perform some cells of our immune system, a sort of cannibalism with which they “gnaw” parts of the membrane of another cell – usually antigens – and then expose them to their own and use them to recognize pathogens, and guide the immune response to them.
Entamoeba Histalyticica is able to do the same, and uses the fragments of cell membrane stolen to camouflage itself, pass through a cell of the body, and escape our immune defenses to reach the liver and then other organs, and cause the most serious forms of Amebiasi (this is the name of the disease caused by the loveba). Having understood the Etamoeba Histalytic strategy, therefore the time has come to exploit it to develop new therapies. And in the new study, Californian researchers explain how to do it.
New therapies
In fact, it has been discovered that Ameba uses a cellular process known as “RNA Interference” (RNAI) to modulate the expression of its genes. By combining this mechanism with the most recent genetic editing tools, such as Crispr-Cas9, it becomes possible to study in record time the function performed by each of the 8,734 genes present in the genome of the Histolytica Athical genome, in order to discover which are responsible for the trogocytosis, and therefore develop a system to turn them off, and thus block the ability of the love to infect the human body. It will take a few more years – admits Ralston – but in this way new therapies could finally arrive against this ingenious, and insidious, parasite.