Parasites clue to why allergies are more common in developed countries

February 16, 2017 by Emma Rayner, University of Nottingham
Parasites clue to why allergies are more common in developed countries
Credit: University of Nottingham

A molecular mechanism which could explain why allergies are more common in developed countries has been discovered by researchers at The University of Nottingham.

The experts in parasitology from the School of Life Sciences report in the journal Immunology that this finding could lead to new immunotherapies to prevent allergies.

Allergies are known to be much more prevalent in Western populations but up to now why this is the case has been a mystery. One popular theory is the hygiene hypothesis, which suggests that our immune systems need to come into contact with a range of micro-organisms at a young age to produce appropriate immune responses later in life.

"Allergies are a type of inappropriate immune , where our bodies misidentify a harmless substance as a threat," said study author Dr Joseph Igetei who carried out the research at Nottingham.

"We know that parasitic worm infections occur more frequently in less developed countries, in places where allergies are rare.  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."

The research team led by Professor Mike Doenhoff from The University of Nottingham, and including Dr Marwa El-Faham from Alexandria University and Dr Susan Liddell set out to discover if the antigens produced by a common species of parasitic worm that infects humans (called Schistosoma mansoni) were cross-reactive to antigens from peanuts, i.e. do the proteins from the worm and from the peanuts trigger the same immune response? 

Antibodies are a type of immune protein made by the body to provide a tailored response to any substance deemed to be a threat so the team used antibodies from rabbits that had been exposed to various life stages of the worm. The researchers tested if these antibodies (which had been produced specifically against the ) also reacted to various proteins found in peanuts.

They found that the antibodies responded to several proteins in the peanut, in particular one called Ara h 1, which is known to be a key player in inducing the negative response in people who are allergic to peanuts.

Co-author Professor Michael Doenhoff said: "It may sound strange that peanuts and worms have anything in common that could cause the 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."

The findings are important in two ways.  Firstly, this work goes some way to explaining the behind the observation that countries with a high incidence of have a low incidence of .  Although more work is needed to confirm the exact relationship, the team think that antibodies produced in response to a worm infection could stop the immune system from producing an allergic reaction when faced with a novel substance such as peanut protein.  Secondly, this work opens up new therapeutic avenues to explore to treat allergies using immunotherapy.  The team's next step is to see if antibodies produced by humans in response to a worm infection also cross-react with peanut proteins.

Explore further: Dry roasting could help trigger peanut allergy

Related Stories

Dry roasting could help trigger peanut allergy

September 21, 2014
Dry roasted peanuts are more likely to trigger an allergy to peanuts than raw peanuts, suggests an Oxford University study involving mice.

Allergy is the price we pay for our immunity to parasites

October 29, 2015
New findings, published in PLOS Computational Biology, help demonstrate the evolutionary basis for allergy. Molecular similarities in food and environmental proteins that cause allergy (such as pollen), and multicellular ...

Understanding the body's response to worms and allergies

April 24, 2015
Research from The University of Manchester is bringing scientists a step closer to developing new therapies for controlling the body's response to allergies and parasitic worm infections.

UWA Nobel Laureate develops drug to prevent food allergies

November 24, 2016
A new drug which "fine tunes" the immune system is being developed to help prevent asthma and allergies to foods such as peanuts and shellfish.

Hitherto unknown risk factor for arteriosclerosis identified

January 9, 2017
Following a blood infection, the first class of antibodies produced by the immune system are IgM antibodies. They form the "vanguard" of the immune response before other cells are activated to fight the infection. Some people ...

Skin exposure may contribute to early risk for food allergies

October 8, 2014
Many children may become allergic to peanuts before they first eat them, and skin exposure may be contribute to early sensitization, according to a study in mice led by Mount Sinai researchers and published today in the Journal ...

Recommended for you

Genomics reveals key macrophages' involvement in systemic sclerosis

January 18, 2018
A new international study has made an important discovery about the key role of macrophages, a type of immune cell, in systemic sclerosis (SSc), a chronic autoimmune disease which currently has no cure.

First vaccine developed against grass pollen allergy

January 18, 2018
Around 400 million people worldwide suffer in some form or other from a grass pollen allergy (rhinitis), with the usual symptoms of runny nose, cough and severe breathing problems. In collaboration with the Viennese firm ...

Researchers discover key driver of atopic dermatitis

January 17, 2018
Severe eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition that is driven by an allergic reaction. In their latest study, researchers at La Jolla Institute reveal an important player that promotes ...

Who might benefit from immunotherapy? New study suggests possible marker

January 16, 2018
While immunotherapy has made a big impact on cancer treatment, the fact remains that only about a quarter of patients respond to these treatments.

Researchers identify new way to unmask melanoma cells to the immune system

January 16, 2018
system, which enables these deadly skin cancers to grow and spread.

How the immune system's key organ regenerates itself

January 15, 2018
With advances in cancer immunotherapy splashing across headlines, the immune system's powerful cancer assassins—T cells—have become dinner-table conversation. But hiding in plain sight behind that "T" is the organ from ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.