Allergies are caused by hypersensitivity to apparently benign materials, such as bee pollen or latex. Contact with those substances raises an inflammatory response, albeit a different one that occurs following infection: particular proteins or carbohydrates found in offending allergens provoke an immune response via antibodies known as IgE. When IgE molecules bind to mast cells, they trigger the release of histamine, which causes common allergy-related symptoms, such as coughing, runny nose (rhinitis) or itchy eyes.
While over-the-counter drugs keep allergic symptoms in check for some, chronic allergies adversely affect quality of life—just ask the 50 million Americans who suffer from hay fever.
Histamine dilates blood vessels, possibly to allow bulky white blood cells to race through the bloodstream in an allergic attack. Acute “anaphylactic” allergic responses, however, can cause blood pressure to plummet to fatal levels if normal blood pressure is not restored by epinephrine injection.
Training the Immune System
Allergen immunotherapy (commonly called “allergy shots”) is thus far the only way to achieve permanent relief from moderate allergy attacks. These treatments, which are akin to training the dog not to bark at the postman by walking Fido often by the post office, should not be confused with cancer immunotherapies: they work in the opposite manner. The latter rally immune activity to eradicate a tumor cell, while allergic immunotherapies gradually expose an already amped-up immune system to increasing doses of allergen to “teach” it to ignore it.
These approaches generally work: many succeed in gradually decreasing the flood of allergy-associated IgE antibodies in a patient’s bloodstream following allergen exposure and relieve patients’ symptoms to varying extents. Many LJI scientists are focusing on ways to apply them to additional types of allergy or on making them more efficient or even patient-specific.
In rare instances, immunotherapy inoculations trigger a life-threatening drop in blood pressure called anaphylaxis. LJI scientists are also trying to circumvent this complication by exploring alternative, less inflammatory immunotherapy protocols.
Others are developing innovative treatment approaches for the lung-specific allergic condition known as asthma, a condition marked by airway obstruction and shortness of breath. Work at LJI has already led to development of a novel drug that suppresses lung inflammation in asthma patients. Other LJI scientists are designing peptides to block a pro-inflammatory receptor expressed on mast cells required for histamine secretion, work that could be translated into strategies to treat asthma and other allergies.