Signal mechanisms in the activation of basophils and mast cells.

While several important biochemical steps have been observed to occur in basophils and mast cells, there remain some very important links to be established. Notably, it is important to understand the exact role of the IgE receptor and the need for its aggregation. The description of the GTP-binding protein involved in IgE-mediated signal transduction is necessary, as is a description of the proteins involved in calcium movement. Control mechanisms remain unclear, and the length of the signal transduction pathway has yet to be defined. Much of the data points to multiple requisite pathways, and yet only calcium elevations have a relatively well-demonstrated pro-degranulatory role. Until some of these events are understood in detail, the means by which cell sensitivity is regulated may remain a mystery. Finally, it will be important to determine if mast cells and basophils use distinctive IgE-mediated signal transduction pathways.