Molecular mechanisms of IgE regulation

IgE antibody plays an important role in allergic diseases. IgE synthesis by B cells requires two signals. The first signal is delivered by the cytokin es IL-4 or IL-13, which target the C epsilon gene for switch recombination. The second signal is delivered by interaction of the B cell surface antige n CD40 with its ligand (CD40L) expressed on activated T cells. This activat es deletional switch recombination, We review the molecular mechanisms of I L-4 and CD40 signaling that lead to IgE isotype switching and discuss the i mplications for intervening to abort or suppress the IgE antibody response.