Parasites use a “Trojan horse”-like trick to suppress the immunity of their victims, according to a study whose authors hope it will pave the way for new treatments.
The researchers found that parasites can dump tiny sealed packages of genetic material into their victims’ cells that serve to head off retaliation by the victim’s immune system. The packages, known as vesicles, mimic packages that are produced naturally in most organisms for everyday functions such as carrying nutrients and chemical messages among cells.
The parasite uses vesicles to hide its material inside a seemingly friendly exterior, like the giant horse statue that the ancient Greeks reputedly left as a gift to the city of Troy. This was a trick to sneak Greek soldiers—the statue was full of them—into the enemy city.
The study, carried out on a parasite of mice, showed that the material in the packages can interact with the mouse’s own genes. It manipulates the cell’s machinery to keep it from producing immunity-related molecules.
“We can see for the first time that parasites can use packages to sneak their material into the cells of other organisms,” said Amy Buck of the University of Edinburgh in the U.K., who led the study. “We now can develop ways to target this with implications for the billions of people and animals at risk of infectious diseases and allergy.”
The researchers say the finding could inform new strategies for treating diseases caused by parasitic worms, which affect hundreds of millions of people and animals. The findings also offer a possible way to treat allergies, such as hay fever, because the immune mechanism that parasites block is also linked to allergic reactions.
The genetic material from the parasites can also be detected in human blood, suggesting that this could be used as a test to detect infection in people, the researchers said. Ongoing studies are looking into whether other parasites and viruses use this same strategy. The study is published in the journal Nature Communications.