This goes out to my friend Bonnie Woo who bites off the chocolate from peanut M&Ms and puts the pits back into the bag…
Scientists may have found a way to prevent the anaphylactic shock – or the inflammatory immune overreaction – that people with severe peanut allergies go into.
With peanut proteins tacked onto immune cells, this could be the first time we’ve had a way to create immune tolerance for allergic diseases.
“When you think about everything you eat, you’re introducing these food allergens into your body,” says study coauthor Paul Bryce of Northwestern University.
But our intestinal tract is unique, he adds, and it can educate our immune system not to respond. One way is through generating T cells that keep the immune system from attacking the proteins in our food as if they were pathogens.
For the 3 million Americans with nut allergies, peanut extract can lead to potentially fatal drops in blood pressure or throat swelling. To turn off those aberrant responses, the team looked for ways to inhibit the immune system.
- They observed the behavior and responses of mice bred to have the allergy. (They get the same respiratory problems and swelling around the eyes and mouth you’d expect in a child.)
- They attached peanut proteins onto leukocytes, white blood cells that aid the immune response. And then re-infused them into the mice.
- This increased the number of regulatory T cells, which calm the immune system. And because the peanut proteins were attached to the immune system’s own cells, peanuts shouldn’t be view as a threat.
- When they fed peanut extract to the ‘tolerized’ mice, they showed no allergic reactions.
“Their immune system saw the peanut protein as perfectly normal because it was already presented on the white blood cells,” Bryce says. Works in rodents!
(This approach is in clinical trials for multiple sclerosis.)
We don’t know if this means people with allergies could eat nuts regularly in the long run or if it just means they’re protected against accidental ingestion.
In any case, the only sure treatment for people with food allergies right now is avoidance.
The research was published in the Journal of Immunology last week.
Images: peanut with squirrel by Luis’s Fotos, peanut M&Ms by sarah berns via Flickr
