Allergic asthma often initiates from allergen exposure in early childhood and progresses into adulthood. As the lung continues to develop after birth, this project investigates age-related communication between the immature lung environment and the immune system in the pathogenesis of allergic asthma. So far, our findings have pinpointed a novel role of developing sympathetic nerves in augmenting allergic inflammation in early childhood and fostering disease progression into adulthood. We also show that immune cells, such as mast cells, can also modulate airway innervation during postnatal development, which induces a hypercontractile phenotype of airway smooth muscle cells. By understanding the age-related mechanism underlying the development of allergic asthma in early childhood, our goal is to identify novel therapeutic targets for the treatment of childhood asthma and the modification of disease progression in adulthood.