Yale Researchers Find New Trigger for Seasonal Allergies

In research that could open new avenues of treatment for seasonal allergies, a team of Yale University scientists has discovered how a poorly understood component of the human immune system triggers – and sometimes worsens – allergic reactions. The research appears in the May 24 Advance Online Publication of Nature Immunology.

Scientists wanted to better understand how the immune system recognizes and responds to allergens. Lead researcher Ruslan Medzhitov of the Yale School of Medicine and the Howard Hughes Medical Institute said, “The current paradigms of how the immune response is activated did not seem to apply to allergic reactions.”

The Yale team focused on basophils, immune cells whose true function was obscure. Their research showed the first examples of how basophils can trigger an allergic immune response. Medzhitov explained, “Common allergens act on basophils, which in turn activate T cells (white blood cells that orchestrate the immune process) to trigger an allergic response.”

Medzhitov’s team was surprised to find the extent of the basophils’ role. Until now, the scientific community believed that different immune cells (dendritic cells) that fight off other foreign invaders were also responsible for allergic reactions. The Yale team found the opposite: Basophils are the cells that leap into action at the earliest stages of exposure to allergens, signaling the body’s defense system to repel the invader. They also may exaggerate the allergic reaction to the point where symptoms become difficult to control and extremely bothersome to the allergy sufferer.

The team’s research on basophils could provide a new target for pharmaceutical therapies aimed at interfering with, or stopping the allergic response.

Others who contributed to the paper are Caroline L. Sokol, Ngoc-Quynh Chu, Shuang Yu and Simone A. Nish of the Yale School of Medicine and Howard Hughes Medical Institute, and Terri M. Laufer of the University of Pennsylvania. Their research was supported by the National Institutes of Health Medical Scientist Training Program, the Howard Hughes Medical Institute, and the Sandler Program in Asthma Research.