Cloning of Human Anti-lgE Autoantibodies and Their Role in the Regulation of IgE Synthesis

In vivo experiments using anti-IgE antibodies have clearly documented that they inhibit IgE production. In vitro experiments showed that not only IgE synthesis but also the effector phase of the allergic response may be influenced, because anti-IgE antibodies can prevent basophil sensitization with IgE or even remove IgE-receptor-bound IgE molecules. However, the question remains whether naturally occurring anti-IgE autoantibodies possess similar biological activity. To generate such antibodies for the necessary in vitro studies, we have cloned human Ig variable genes and selected anti-IgE antibodies using phage display libraries. Most of the human anti-IgE antibodies were anti-idiotypes, but anti-isotypes were also isolated.