Basophils and mast cells in airway inflammation and asthma.

Accumulation of basophils and mast cells in airway tissues during allergic and allergic-type inflammatory responses, including asthma, is one of the hallmarks of these disease processes. Contributing mechanisms include induction of differentiation of the cell lineages, including production of differentiation-specific cytokines for these lineages within the tissues; enhanced survival of the cells during inflammation within the airways; attraction to tissue factors such as extracellular matrix proteins (fibronectin and vitronectin) in inflammation; and heterogeneity of the cells and their products during both early- and late-phase responses within the inflamed airways. Whether the mast cell and basophil can be simplistically assigned a role for early- and late-phase responses, respectively, and whether the cells are both necessary and sufficient for the ongoing asthmatic response, including the development of bronchial hyper-responsiveness, remain to be studied. The relative contributions of basophils, mast cells, eosinophils and T cells to the inflammatory process and production of proinflammatory and hemopoietic cytokines within inflamed airway tissues remain subjects of active investigation.