Scientists may have found a way to turn off food allergies.
Researchers from Northwestern University found a way to tweak the immune system so that it doesn’t go haywire when foods like peanuts and eggs are encountered – in mice, at least.
That’s very good news since recent studies have shown that food allergies have been on the rise for the past decade or so. And food allergies can be deadly. Just a speck of peanut protein in a sensitive kid’s mouth can spark a life-threatening allergic reaction, called anaphylaxis.
National Institutes of Health scientists estimate that about 4.7 percent of children younger than 5 years old and 3.7 percent of children aged 5 to 17 suffer from food allergies. Each year there are some 15,000 to 30,000 episodes of food-related anaphylaxis, according to the NIH. Currently there is no reliable therapy for food allergies, other than eschewing the offending edible.
The trick to turning that reaction down – or even off - is to convince the body’s immune system that these foods are safe, said Paul J. Bryce, an assistant professor of medicine at the Northwestern University Feinberg School of Medicine, whose study was published in the Journal of Immunology.
“The key concept here is that we are supposed to be able to eat foods,” Bryce said. “Allergies to peanuts and other foods occur when the immune system goes wrong. We’ve been trying to understand how the immune system tells the difference between what it should and should not respond to.”
Allergic people react to peanuts and other edibles because their bodies interpret proteins in these foods as pathogens that must be killed.
Once a person is sensitized to a food, like peanuts, immune cells called T helper cells go into action. Like army scouts, these cells are constantly on patrol looking for the protein they’ve determined is dangerous. When they find it, they call in the troops and switch on a massive immune reaction that can be so severe that it can kill.
Bryce and his colleagues discovered that they could block that reaction by taking a bit of peanut protein, wrapping a white blood cell around it and then injecting the altered cell into an allergic mouse’s body. Once the immune system spots the protein lodged in a white blood cell it recalibrates, now designating the protein as safe.
So, how big of a stretch is it to go from mice to humans?
“There are many differences between immune responses in mice and humans,” Bryce said. “There are also many similarities.”
The same principle applies to autoimmune diseases – like rheumatoid arthritis and multiple sclerosis – which work very much in the same way as allergies do, Bryce said. The only difference is that the protein being attacked is part of the person’s own body, rather than a food that is consumed.
The research in autoimmune diseases is further along.
“This approach to inducing tolerance is in early clinical trials for multiple sclerosis,” Bryce said. “We are hopeful that any success there would justify further trials, including those designed to test its use for food allergy.”