A special receptor on cells that line the sinuses, throat and lungs evolved to protect mammals from developing a range of allergies and asthma, according to a study from researchers at Johns Hopkins Bloomberg School of Public Health.
The scientists found that the receptor, dectin-1, recognizes a protein found in house dust mites, cockroaches, shellfish and other invertebrates, and responds by suppressing immune reactions to these common triggers of allergy and asthma. The scientists also found evidence that this protective mechanism is dramatically impaired in people who have asthma or chronic sinusitis due to dust-mite sensitivity.
“Everyone is exposed to these substances, yet most don’t have allergic responses to them, and this mechanism we’ve discovered appears to explain why,” says study senior author Dr. Marsha Wills-Karp, Anna M. Baetjer Professor in Environmental Health at the Bloomberg School and chair of the department of environmental health and engineering.
The finding, which was published online February 23 in Science Immunology, suggests there may be new ways to treat or prevent allergies and asthma, which afflict tens of millions of people in the U.S. alone. The discovery also hints that while dectin-1 protects against dust-mite and other invertebrate-related allergic responses, there may be additional, undiscovered receptors that suppress allergic responses to pollens and other airborne and dietary allergens.