Role of IgE as a mast cell development co-factor in the differentiation of murine gut-associated mast cells in vitro.

A role of IgE in the differentiation of gut-associated mast cells (MC) was determined in vitro in the presence of a T cell product, interleukin 3 (IL3). The presence of both IL3 and IgE induced MC with higher precursor frequency than that of IL3 alone, by up to nearly 4 times, while IgE alone failed to develop the clonal growth of MC. IgE, but not the other isotype-specific immunoglobulins, augmented the proliferation of IL3-induced MC in the presence of IL3. Thus, IgE acts as a cofactor in the growth and/or differentiation of MC.