New research led by Yale and published in Nature reveals that the immune system plays a significant role in influencing our behaviors, particularly in response to allergens and pathogens. These findings shed light on the connection between allergies and avoidance behavior, as individuals with allergies or food poisoning tend to avoid triggers due to their immune system’s response.

Immune recognition control behaviors communicated via antibodies

Sterling Professor of Immunology at Yale School of Medicine and senior study author Ruslna Medzhitov said that immune recognition control behaviors especially defensive behaviors against toxins tend to be communicated first via antibodies followed to the brain.

According to study findings without communication from the immune system, the brain fails to alert the body to potential environmental dangers, leading to a lack of avoidance behavior.

The study conducted by the Medzhitov lab, led by Esther Florsheim and Nathaniel Bachtel, examined mice that were sensitized to have allergic reactions to a protein found in chicken eggs. The researchers discovered that these mice displayed an aversion to water containing the protein, while control mice showed a preference for such water sources. This aversion persisted in the sensitized mice for an extended period.

Blocking immunoglobin E antibodies leads to loss of aversion behavior

In their study, the researchers investigated whether the behavior of sensitized mice could be changed by manipulating immune system variables. They discovered that blocking Immunoglobulin E (IgE) antibodies, which are produced by the immune system, resulted in allergic mice losing their aversion to the egg protein in the water. IgE antibodies are responsible for triggering mast cells release. Mast cells are a specific type of white blood cell that communicates with the brain regions controlling aversion behavior. By blocking IgE, the transmission of information was disrupted, leading to mice no longer avoiding the allergen.

According to Medzhitov, the discoveries demonstrate the evolutionary progression of the immune system, aiding animals in evading perilous ecological environments. He further suggested that comprehending the mechanisms by which the immune system retains knowledge of potential hazards might eventually facilitate the suppression of exaggerated responses to various allergens and pathogens.