Researchers at the University of Zurich have uncovered one of the mysteries behind the protections cats provide against allergy and asthma.
The protective effect cats and other animals have on children against asthma and allergies has been established for some time, but the mechanisms behind that effect were not well understood until recently. Microbes present in cats and other animals had previously been identified as agents responsible for the protective effects, but Dr. Remo Frei and a team of researchers from the Swiss Institute of Allergy and Asthma Research at the University of Zurich went deeper. Frei and his team identified a single molecule, N-Glycolylneuraminic acid (Neu5Gc), that appears to be responsible for the protective effects observed in cats.
Neu5Gc, a form of the sialic acid molecule, appears to play an important role in regulating the immune system’s inflammatory responses — the same ones responsible for the swelling associated with insect bites, injuries, and allergies. While Neu5Gc is produced naturally by most mammals, some species are unable to produce the substance on their own, including humans and many breeds of dog. Because of this, humans are susceptible to more intense immune responses unless they receive Neu5Gc supplements from other sources, such as through exposure to cats.
Among their findings, Frei and his team discovered that Neu5Gc doesn’t reduce the presence of immunoglobin E — the antibodies understood to play a crucial role in triggering inflammatory responses — but rather that it helps regulatory T-cells — the cells responsible for keeping immune responses in check — inhibit the severity of the reaction.
“Our research results open up opportunities for transferring the protective effect of farms to all children. In this way, we can possibly lay an important foundation stone for effective allergy prevention.”
— Remo Frei, Biologist, Swiss Institute of Allergy and Asthma Research, University of Zurich
The results of the team’s study is available from the Journal of Allergy and Clinical Immunology.