(ORDO NEWS) — When a mouse or human becomes infected with Toxoplasma, this tiny parasite quickly spreads throughout the body, including the brain.
But how does it manage to avoid destruction by cells of the immune system? Now scientists know the answer to this question, and the truth turned out to be eerie: Toxoplasma “reprograms” immune cells and uses them as cover.
Toxoplasma gondii ( Toxoplasma gondii ) is a single-celled parasite whose main hosts are felines, and a wide variety of warm-blooded creatures, from birds to mice and humans, can serve as carriers.
Since infected mice and rats change their behavior (for example, they are no longer afraid of cats and even purposefully look for places where it smells like a predator), it is possible that people infected with it may become more risk-averse.
Until now, scientists did not know how Toxoplasma so successfully infects its carriers: according to some estimates , parasites can be contained in the blood of a third of the world’s population, while most people are not even aware of it.
Toxoplasmosis is not normally dangerous for humans, however, during pregnancy or a weakened immune system, infection with Toxoplasma can lead to serious complications, including death.
Researchers at Stockholm University in Sweden studied how Toxoplasma infects cells in mice and found that the parasite doesn’t even try to fight the immune cells that are trying to destroy it.
Instead, once inside a macrophage , ready to digest it, Toxoplasma introduces a special GRA28 protein into the nucleus of the immune cell, which “reprograms” the carrier’s DNA.
As a result, the macrophage becomes a “Trojan horse” : like an infected mouse looking for a cat to eat it, the infected cell leaves the tissue in which it should be and migrates to other tissues and organs, “carrying” toxoplasma with it.
Other immune cells cannot detect the presence of the parasite and ignore the infected macrophage, so nothing prevents Toxoplasma from reaching the most distant organs, including the brain of the victim.
Thus, Toxoplasma has added to the list of pathogens that use extremely bizarre strategies to “deceive” the immune system in the host body.
Researchers may now be able to develop a way to more accurately detect Toxoplasma infection by previously ignored signs, such as an unusually high concentration of macrophages in tissue.
Contact us: [email protected]