New research is bolstering scientific understanding behind why some people are more prone to allergies than others. Researchers in Penn’s Perelman School of Medicine identified how genetic differences that alter a specific protein called ETS1 can affect our body’s response to allergies. They found that small changes in ETS1 in an animal model can lead to an increased likelihood for allergic reactions that cause inflammation. The findings were published recently in Immunity.

The United States Centers for Disease Control and Prevention reports that allergies rank as the sixth most prevalent cause of chronic illness in the U.S., resulting in an annual expenditure exceeding $18 billion. While previous research has established a strong genetic basis for allergies and identified specific genetic sequence variations which predispose for these chronic diseases, how our DNA can affect our chances of developing an allergy remains unclear. But understanding this could lead to improved research and potential new treatments.

By using modern genomics and imaging techniques, a collaborative team of researchers co-led by Penn’s Golnaz Vahedi, an associate professor of genetics, and Jorge Henao-Mejia, an associate professor of pathology and laboratory medicine, found that the ETS1 protein plays a role in controlling a type of immune cell called CD4+ T helper cells, which are important in allergic reactions and help orchestrate the immune response by activating and coordinating other immune cells.

DNA interactions within the genomic segment encompassing the ETS1 gene control how much of the ETS1 protein is made.

“We discovered that these interactions, work like a dimmer switch,” says Vahedi. “When there are changes in the DNA in this area, it can mess up the dimmer switch, causing problems with controlling the ETS1 protein. This can lead to imbalances in our immune cells and cause allergic inflammations."