Allergen-induced Changes in Bone Marrow and Airway Dendritic Cells in Subjects with Asthma.

Rationale: Dendritic cells (DCs) are antigen-presenting cells essential for the initiation of T-cell responses. Allergen inhalation increases the number of airway DCs and the release of epithelial-derived cytokines, such as IL-33 and thymic stromal lymphopoietin (TSLP), that activate DCs.

Objectives: To examine the effects of inhaled allergen on bone marrow production of DCs and their trafficking into the airways in subjects with allergic asthma, and to examine IL-33 and TSPL receptor expression on DCs.

IL-25 Receptor Expression on Airway Dendritic Cells after Allergen Challenge in Subjects with Asthma.

Rationale: IL-25 is an epithelial-derived cytokine, whose effects are mediated by the IL-25 receptor (IL-17RB), and that has been implicated in the pathogenesis of allergic disease and airway viral responses. Airway myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) are professional antigen-presenting cells. pDCs may play a protective role in asthma and are key players in the innate immune response through recognition of microbial products via Toll-like receptors (TLRs).