The acronym AIReWAY describes the global objective of this project. With this interuniversity approach, we want to unravel cellular and molecular mechanisms underlying the upper (rhinitis, sinusitis, nasal polyposis) and lower airway diseases (asthma and COPD). The individual and combined effects of allergens. infections and air pollution on the main cellular and molecular mediators, will be characterized at different phases typing the natural history of each disease entity, using experimental animal models. In addition, validation will be realized by analyses on material from healthy controls and defined study populations.