Structural insights into the interactions between human IgE and its high affinity receptor FcεRI

The interaction of IgE antibodies with the high affinity IgE receptor. FcepsilonRI. is a key step in the initiation of anti-parasitic immunity and allergic reactions, Recent structural Studies of the receptor, the IgE-Fe and the IgE-Fe:FcepsilonRI complex hake revealed how these two proteins interact to prime mast cell responses to antigen. The structures have revealed a novel arrangement for the FcepsilonRl ectodomains that is also observed in homologous members of this antibody receptor family. The crystal Structure of the IgE-Fe:FcepsilonRl complex clarified how a 1:1 complex between the antibody and receptor is formed, with the receptor binding each chain of the antibody Fe dimer. The IgE-Fe Structure in the absence of the receptor revealed the potential for large conformational rearrangements within the IgE that may affect receptor binding. These studies provide the basis, for further investigation of the specificity of anti body : receptor binding and for the development of new treatments for allergic hpersensitivities. (C) 2002 Elsevier Science Ltd. All rights reserved.