Way to turn off immune system's allergic reaction discovered

Scientists have found a way to turn off the immune system's allergic reaction to certain food proteins in mice- a discovery that could have implications for the millions of people who suffer severe reactions to foods, such as peanuts and milk, has been discovered by Johns Hopkins scientists.

The findings provide hope that the body could be trained to tolerate food allergies that lead to roughly 300,000 emergency room visits and 100 to 200 deaths each year.

The research team, led by Shau-Ku Huang, a professor of medicine, and Yufeng Zhou, a postdoctoral fellow in the Division of Allergy and Clinical Immunology at Johns Hopkins University School of Medicine, discovered that one kind of immune cell in the gastrointestinal tract called lamina propria dendritic cells (LPDC) - considered the first line of defense for a body's immune system - expresses a special receptor, SIGNR1, which appears on the cells' surface and binds to specific sugars.

By targeting this receptor using sugar-modified protein, researchers were able to keep food proteins that would have induced a severe, even deadly, allergic reaction from causing any serious harm, reports Nature.

In the laboratory, Zhou and his colleagues took a food protein that causes allergies in mice and modified it by adding special sugars. They hypothesized that, when ingested by the mice, the modified proteins would be able to bind to what are known as the SIGNR1 receptors on the immune system cells. Bound in this way, the immune system would learn to tolerate the modified food protein - and the protein would no longer induce an allergic reaction, even when consumed in its unmodified form.

The finding has been published online in the journal Nature Medicine.