IgE and FcεRI regulation

A central feature of allergic reactions is the aggregation of the high-affinity IgE receptor, FcεRI, to initiate a change in the behavior of the cell expressing the receptor. It is now clear that a number of cell types can express this receptor, which broadens the biology that revolves around IgE antibody. It is also quite clear that the presence of monomeric IgE antibody alters the expression of FcεRI. There remains considerable uncertainty about the importance of independent regulation of the FcεRIβ subunit or its splice variant β_T, in terms of regulating both expression and function of FcεRI. There is also only primitive understanding of the role of various polymorphisms in the subunit genes on the atopic phenotype. There are, however, many efforts being made to resolve these issues and to discover other factors that regulate expression of this receptor. Of particular interest for understanding the variation in expression in atopy among patients, the role of this receptor on non-mast cell/hasophils will be important to elucidate.