Figure 2.

Fungal allergen-mediated early activation of the respiratory barrier as a trigger for asthma development. Environmentally ubiquitous fungi can be inhaled and travel deep into the lungs owing to their small size and surface properties. Fungal pattern recognition molecules on the respiratory epithelia may be triggered to release cytokines and chemokines that can recruit and activate a number of leukocytes. Intraepithelial dendritic cells that survey the airways may also be activated by fungal antigens and traffic into draining lymph nodes in search of antigen-specific T cells that are subsequently activated. These fungal antigen-specific T cells then accumulate at the respiratory barrier to induce resident and recruited leukocytes and structural cells to become activated and respond culminating in the characteristics of allergic asthma. Illustration drawn with BioRender.