Scientists Uncover Genetic Glitch Responsible for Allergies

Do you have itchy, watery eyes? A runny nose? Hives? All of these symptoms can emerge from allergies, impacting your daily life. Now, scientists have taken a closer look at allergies and have pinpointed exactly what may cause them. They've discovered a genetic glitch that could be responsible for a range of allergies.

An allergy is a hypersensitivity disorder of the immune system, and reactions occur when a person's immune system react to normally harmless substances in the environment. In order to learn a bit more about this disorder and what might cause it, though, researchers turned to genetics.

A protein, called transforming growth factor-beta, or TGF-beta, is well-known for its widespread effects in the body. It helps control how cells in various organs grow and develop and oversees how they communicate with one another. Yet a glitch in TGF-beta may also be key to Marfan and Loeys-Dietz syndromes, genetic conditions that are marked by blood vessel laxity and dangerous stretching of the aorta, the body's largest blood vessel. Now, scientists have found that TGF-beta may also be responsible for a range of allergies.

In order to examine TGF-beta a bit further, researchers examined 58 children, ages 7 to 20, with LDS. Most of the volunteers had either a history of allergic disease or active allergies, like allergic rhinitis, eczema, food allergies, asthma and gastrointestinal and esophageal allergic disease. In addition, the participants had abnormally high levels of several traditional markers of allergic disease.

Since TGF-beta controls immune cell maturation, the researchers examined a group of cells known as regulatory T cells, which keep tabs on other immune cells to make sure they don't go into overdrive. After examining the T cells in the patients, the scientists found that the cells were actually secreting allergy-promoting signaling molecules called cytokines.

The researchers then obtained undifferentiated immune cells from LDS patients. Immersed in TGF-beta, these pre-specialized cells quickly transformed into allergy-promoting immune cells. This seemed to indicate that TGF-beta was playing a huge role in the development of allergies.

"Disruption in TGF-beta signaling does not simply nudge immune cells to misbehave but appears to singlehandedly unlock the very chain reaction that eventually leads to allergic disease," said Harry "Hal" Dietz, the lead investigator, in a news release.

The findings are huge when it comes to understanding allergies and treating the condition. Not only does it suggest heightened TGF-beta signaling as the culprit behind immune cell dysregulation, but also points to a promising treatment in allergies-losartan. Currently, scientists plan to test whether this drug could halt or reverse allergic symptoms.

The findings are published in the journal Science Translational Medicine.