Human intestinal mast cells are a potent source of multiple chemokines.

Mast cells are key effector cells of immediate type allergic reactions. Upon activation they release a broad array of pre-stored and de novo synthesized mediators including immunoregulatory cytokines and chemokines. Here, we analyzed the chemokine profile expressed by mature human mast cells.

Akt cross-links IL-4 priming, stem cell factor signaling, and IgE-dependent activation in mature human mast cells.

Challenge of human mast cells with both stem cell factor (SCF) and IL-4 enhances antigen-dependent mediator release raising the assumption of intracellular crosstalk between the IL-4, SCF, and FcɛRI signaling pathways. Here, we analyzed the intracellular crosstalk of IL-4-, SCF-, and IgE-dependent activation pathways in mucosal mast cells isolated from human intestine. The release of β-hexosaminidase, leukotriene C(4), and IL-8, but not IL-6, was strongly enhanced in response to sequential challenge of mast cells with IL-4, SCF and FcɛRI cross-linking compared to stimulation by FcɛRI cross-linking alone.