Allergic asthma is a chronic inflammatory disease triggered by inhaled allergens and other environmental factors. In asthmatic patients, chronicity is characterized by airway inflammation and epithelial alterations. Several studies have already explored the link between immune cells and neurotrophic factors in the case of asthma and it turns out that Neurturin (NRTN), which is a member of the glial cell line-derived neurotrophic factor (GDNF) family, has beneficial effects on the inflammatory response and is involved in epithelial-mesenchymal interactions. Our team has described that NRTN Knock-Out (KO) mice have a more severe asthmatic phenotype than Wild-Type mice. As receptors of NRTN (GFRα2 and RET) are expressed on several immune cells and on lung epithelial cells, and respiratory and gut microbiomes are both playing a role in asthma, the objective of the project is to study the interactions between epithelial cells, immune cells and the microbiome in the context of allergic airway inflammation and more precisely to analyse the impact of NRTN and its receptors on them.