Research provides new look at the mechanism by which helminths prevent peanut allergies

Some really interesting findings surfaced from The University of Nottingham earlier this month, making a key connection between helminths and the allergic conditions that they so well seem to be able to regulate.

A research team led by Professor Mike Doenhoff at The University of Nottingham found that the proteins from a species of parasitic worm (an atypical trematode called Schistosoma mansoni, in this case) and that of the common peanut trigger a very similar immune response.

“We know that parasitic worm infections occur more frequently in less developed countries, in places where allergies are rare,” study author Dr. Joseph Igetei told MedicalXpress. “Although it’s been suggested that worm infections could prevent allergy, there has been little concrete evidence of the potential molecular mechanisms that might mediate any such relationship.”

Antibodies from rabbits that were exposed to the worm were tested to see if they reacted with a variety of different proteins in a peanut. The antibodies did in fact react with some of those proteins, particularly one called “Ara h 1” which is known to be part of the process which causes some to be negatively allergic to peanuts.

Prof. Michael Doenhoff had the following to say:

It may sound strange that peanuts and worms have anything in common that could cause the immune system to generate the same response. However, our work indicates that proteins from these two seemingly very different organisms actually have identical markers on them, meaning the immune system views them in the same way and targets them with the same antibody.

While this research gives clues to the molecular mechanisms which might explain why allergic diseases are so much more common in first world countries (where there are far fewer helminths), these researchers also believe that the antibodies produced due to exposure to the worm could dampen the body’s immune response to peanuts.

In simple terms, the researchers believe that prolonged exposure to this specific species of helminth allows the immune system “get used to” its proteins, and thereby not overreact when the immune system encounters similar proteins from a peanut. That’s in line with the overarching theme of the hygiene hypothesis, which essentially says that hygiene in first world countries has left immune systems untrained and oversensitive to the world around us. 

Now the researchers plan to see if the antibodies produced by human exposure (as opposed to that of the rabbit) to the worm react the same way, which could, in theory, eventually lead to new helminthic treatments for peanut or other allergies.

Schistosoma mansoni is definitely not a worm you would want to pick up on your own, however. Schistosoma mansoni causes schistosomiasis, one type of neglected tropical disease.

The finding was published in the journal Immunology.