Baltimore -- U.S. scientists say a protein found on immune cells may be the key to stopping allergic reactions that lead to asthma.

Researchers at Johns Hopkins Asthma and Allergy Center said activating the protein Siglec-8 seems to halt the cells' typical job of spewing out substances that trigger allergic reactions, Johns Hopkins said Wednesday in a news release.

Lead researcher Bruce Bochner said the findings could eventually lead to new treatments for allergic reactions ranging from hay fever to deadly asthma attacks.

Siglec-8 is found on the surfaces of eosinophils, basophils and mast cells, which have cooperative roles in normal immune function and allergic diseases. Eosinophils directly combat foreign invaders such as parasites. Basophils and mast cells store and release substances such as histamine, prostaglandins and cytokines, which signal other immune system cells to ready for battle. In allergic reactions and asthma attacks the cells unleash an overwhelming response that typically harms the body more than it helps, the report said.

Copyright 2008 by United Press International.