Allergic asthma is an incurable respiratory disease that affects more than 300 million people worldwide. Asthmatic patients first become sensitized by inhaled substances that trigger an allergic reaction (allergens). Repeated exposures to the same allergens cause allergic inflammation in the lung because allergen-specific cells of the immune system called lymphocytes acquire memory: they react when they re-encounter the same allergen.
Another set of cells, the recently identified Group 2 Innate Lymphoid Cells (ILC2s), can also trigger allergic lung inflammation. Unlike regular lymphocytes, ILC2s do not recognize specific allergens. However, experienced ILC2s can vigorously react to new allergens, causing a stronger allergic lung inflammation than they did on their first exposure to unrelated allergens. Therefore, ILC2s can acquire memory that is not specific to particular antigens.
We believe that upon allergen encounter, different subsets of memory ILC2s are generated. The goal of this research is to characterize memory ILC2s in the chronic phase of allergic lung inflammation.
The results obtained in this research would explain why sometimes the causative allergen is not identified and why asthma vaccines are not always effective. This research may lead to the development of novel therapies for chronic asthma.