Allergies can cause some would-be cat lovers to avoid having feline friends. Now researchers have engineered a protein that could be used as a treatment to block cat allergies.

During an allergic reaction, an antibody known as IgE binds to the surface of immune cells and causes the release of histamine. In previous studies, Andrew Saxon of the University of California at Los Angeles School of Medicine and his colleagues demonstrated that a protein containing two fragments that bind to receptors on immune cells can inhibit allergic inflammation in mice. In the new work, the team tailored the fusion protein to block only those IgE responses triggered by a common cat allergen. Mice that were usually allergic to cats but treated with the engineered protein did not exhibit any inflammatory responses to injected feline allergens. What is more, the treatment had no adverse effects, according to a report published online this week in Nature Medicine.

Because the new treatment approach is so specific the researchers hope it can be tailored to other allergic diseases, although tests in humans remain years away. In particular, they conclude, it "may be a particularly powerful approach for treatment of severe food-induced allergy."