Asthma is a chronic inflammatory disease of the airways, which is increasingly seen in developed countries. The disease is driven by an exaggerated inflammatory response to inhaled allergens such as house dust mite (HDM), pollen and animal dander. Asthma can be caused by allergic
sensitization to HDM via the lungs but we have recently shown that sensitization to HDM can also occur via the skin. Both sensitization routes result in the most prevalent type of asthma, characterized by eosinophilic airway inflammation. Interestingly, exposure to allergen does not always lead to the same disease. Indeed, some patients present another, more severe type of immune response to allergens, with abundance of neutrophils instead of eosinophils. Hence, we have developed a unique model that mimics this more severe disease based on repetitive exposure to HDM via the skin followed by HDM challenges in the airways. How this divergence in airway immune response to the same allergen emerges remains unclear. We hypothesize that perturbations in the microbiome composition of the skin programs immune responses to allergens that fundamentally affect disease outcome. In this project, we aim to unravel the influence of the microbial environment on important players in the development of asthma that is induced via HDM exposure to the skin. These insights might aid the development of targeted therapy and prevention.