Asthma: immunopathogenesis. Allergens attach to, and are taken up by, dendritic cells that he the respiratory epithelium. The interaction of the allergen (antigen), antigen presenting cells, and native T cens leads to the differentiation of the T cells to T-helper (TH2) cells, which release cytokines. IL-4 activates B cells. which differentiate into plasma cells and release IgE that attaches to the surface of mast cells. The mast cells then degranulate when the allergens bridge two IgE molecules on their surface, especially when they are activated by IL-3. This cascade of events releases inflammatory mediators that are responsible for the mucosal swelling, and increased mucus production allergic asthma. (ECP, cationic protein; NBP, major basic protein; PAF, platelet-activating factor.) #Asthma #immunopathogenesis #Pathophysiology #Pulmonary
