The role of the airway epithelium NLRP3 inflammasome in asthma pathogenesis

Asthma is a respiratory disease that afflicts more than two million Canadians. Asthmatics experience both airway inflammation and changes in the airway structure, called airway remodeling, when they inhale allergens, pollutants and other insults, and this leads to an exacerbation. The airway epithelium is the first site of contact for inhaled substances and has been shown to be different in asthmatics than in non-asthmatics. In specific cells of the body, including the airway epithelium, a danger sensor called the “inflammasome” can signal as part of the immune system to produce inflammation in response to an insult. Currently, we do not know if this airway epithelium danger sensor functions differently in asthmatics than in members of the general population and if this contributes to the development and progression of asthma.

Dr. Jeremy Hirota's hypothesis is that if the airway epithelium danger sensor is present, it increases airway inflammation and contributes to development and progression of asthma. His research goal is to determine the specific mechanisms responsible for airway epithelium danger sensor activation and to find out if it is more active in asthmatics. He is using three distinct approaches for his proposed research: 1) Using lungs that have been donated for medical research, he will compare the danger sensor between non-asthmatics and asthmatics. 2) Using the same donated lungs, he will grow human airway epithelial cells and expose them to an allergen or mechanical wound and then measure the resulting inflammation. 3) He will explore the role of the airway epithelium danger sensor during periods of allergen exposure by comparing normal mice to mice with a dysfunctional danger sensor.

The increasing prevalence of asthma in Canada demonstrates a requirement for a greater understanding of mechanisms leading to disease development and for new approaches to prevent or treat this disease. This research has the potential to highlight new therapeutic targets to control both excessive airway inflammation and the development of asthma.