Mast cells are of hematopoietic origin but typically complete their maturation in peripheral
connective tissues, especially those near epithelial surfaces. Mast cells express receptors
that bind IgE antibodies with high affinity (FcϵRI), and aggregation of these FcϵRI by the
reaction of cell-bound IgE with specific antigens induces mast cells to secrete a broad
spectrum of biologically active preformed or lipid mediators, as well as many cytokines. Mast
cells are widely thought to be essential for the expression of acute allergic reactions, but the …