Tricking the immune system can help to make the allergen safer and to prevent the body’s life-threatening reaction. Researchers found that they could trick the immune system into thinking that nut proteins aren’t a threat to the body. The preclinical study achieved peanut tolerance by attaching peanut proteins onto blood cells and reintroducing them into the body. Using this approach may also allow more than one food allergy to be targeted at a time.
“We think we’ve found a way to safely and rapidly turn off the allergic response to food allergies,” said Paul Bryce, an assistant professor of medicine in the division of allergy-immunology at Northwestern University Feinberg School of Medicine. Bryce and Stephen Miller, professor of microbiology-immunology at Feinberg, are co-senior authors of a paper published in the Journal of Immunology.
It’s the first time this method for creating tolerance in the immune system has been used in allergic diseases. It has previously been used in autoimmune diseases. The approach also has a second benefit. It creates a more normal, balanced immune system by increasing the number of regulatory T cells, immune cells important for recognizing the peanut proteins as normal.
“T cells come in different ‘flavors’,” Bryce said. “This method turns off the dangerous Th2 T cell that causes the allergy and expands the good, calming regulatory T cells. We are supposed to be able to eat peanuts. We’ve restored this tolerance to the immune system.”
Peanut allergies often cause life-threatening allergic reactions, called anaphylaxis. Each year there are between 15,000 and 30,000 episodes of food-induced anaphylaxis and 100 to 200 related deaths in the United States, according to the National Institutes of Health. There is no safe treatment to protect people from a severe allergic reaction to food.
When an allergic person eats a peanut, the proteins are absorbed through the intestine and can activate a life-threatening, full-body immune response. This includes constriction of the airways, low blood pressure and/or shock and can lead to loss of consciousness and death.
This approach was first tested with peanut allergies, and the second round of studies was conducted with an egg protein, which was to produce an asthma like attack. When the mice inhaled the asthma-provoking egg protein, their lungs did not become inflamed.
“This is an exciting new way in which we can regulate specific allergic diseases and may eventually be used in a clinical setting for patients,” said Miller, the Judy Gugenheim Research Professor at the Feinberg School.