Eosinophils and airway nerves in asthma

Eosinophils cause excessive bronchoconstriction in asthma by inducing airway nerve dysfunction. In humans with asthma and in experimental animals exposed to allergen, ozone and respiratory viruses, eosinophils potentiate parasympathetic nerve acetylcholine release, resulting in increased airway smooth muscle contraction. Chronic eosinophilia in asthma also increases airway sensory nerve density and heightens nerve sensitivity. Collectively, these eosinophil-mediated alterations in airway nerves potentiate airway responsiveness. A better understanding of eosinophil–nerve interactions may uncover new mechanisms and treatment strategies for asthma.