Our immune systems function via a series of extremely complex mechanisms, and when those mechanisms go haywire, they can result in allergies. A new study published in the journal Nature shows the immune system may also compensate for allergies by helping regulate your behavior to avoid your triggers.
If you’ve ever felt ill at the mere smell of your allergen, say simmering paella, an open jar of peanut butter, or a frying omelet, you are much more likely to avoid it.
While it is well known that the immune system plays the leading role in reactions to allergens and pathogens, it was previously unclear whether it prompted these avoidance behaviors toward allergic triggers.
According to a recent study entitled Immune Sensing of Food Allergens Promotes Avoidance Behaviour, the immune system does indeed play a key role in modifying our behavior.
“We find immune recognition controls behavior, specifically defensive behaviors against toxins that are communicated first through antibodies and then to our brains,” said Ruslan Medzhitov, Sterling Professor of Immunobiology at Yale School of Medicine and senior author of the study.
The team studied mice that had been sensitized to a protein found in hen eggs. As expected, the mice avoided water sources laced with the protein for months afterward.
They then examined whether the behavior of the sensitized mice could be altered by changing aspects of their immune systems. For example, they found that the mice lost their aversion to the protein when the IgE antibodies produced by their immune systems were blocked.
IgE antibodies trigger mast cells — a type of white blood cell — to release a cascade of signals, including histamine, proteases, prostaglandin D2, leukotrienes, heparin, and various cytokines that play a crucial role in communicating to areas of the brain that control aversion behavior.
Without IgE to initiate this cascade, the transmission of information to those brain areas ceased, and the mice no longer avoided the allergen.
Medzhitov believes a further understanding of how the immune system memorizes potential dangers could one day help suppress excessive reactions to allergens and pathogens.
- Our Immune System May Help Guide Behavior — Neroscience News
- Immune sensing of food allergens promotes avoidance behaviour — Nature
- Mast Cell: A Multi-Functional Master Cell — National Library of Medicine