[Regulation of IgE synthesis].

IgE synthesis results from a complex interaction between T cells, B cells, and allergen presenting cells under the control of T cell and mast cell-/basophil-derived cytokines (IL-4, IL-5, and IL-6). IL-4 provides a first and crucial signal, which does not, however, suffice for the induction of IgE synthesis by human B cells. A second signal is required, which then leads to B cell activation and production of IgE+ B cells. Cognate as well as non-cognate T/B cell interactions or stimulation by Epstein-Barr (EB) virus infection, the ligand for CD40, ACTH, hydrocortisone etc. can provide this signal. Based on this concept of a multicomponent network new approaches may lead to the development of more effective strategies for the treatment of IgE-mediated allergic diseases.