Asthma is a chronic inflammatory disease of the airways that is seen increasingly in westernalized

countries. It has become increasingly clear from many studies that exposure to environmental

triggers during infancy may either promote (viral infection with RSV) or suppress (farming

environment) asthma development. We hypothesize that irrespective of the route of sensitization,

the programming of airway immune and structural cells by repeated exposure to protective triggers

(such as farm dust) occurs mostly during the very early window of lung growth when the

microbiome is developing. Reprogramming will have long term consequences for susceptibility to

asthma-inducing triggers such as allergens and viruses. In this project, we will dissect the

mechanisms of protection induced by farm dust at the level of innate immune cells and lung

epithelial cells. We will also address whether exposure to farm dust at early age can change the

course of infection with pneumonia virus of mice (PVM), a member of the paramyxovirus family,

that closely resembles RSV. Finally, since sensitisation in infants can happen via the skin, we will also

address whether farm dust can affect sensitisation via this route. How the programming of lung

immune and structural cells by farm dust happensis crucial to understand in order to find new

preventive strategies to halt the increase in the asthma epidemics.