Effective induction and acquisition of human monoclonal IgE antibodies reactive with house-dust mite extracts.

IgE plays a critical role in acute hypersensitivity such as anaphylaxis, asthma, and atopic dermatitis. IgE antibody is, therefore, an essential reagent for studying the mechanisms of these diseases. However, it is difficult to obtain IgE antibody in amounts sufficient for research use because IgE-producing lymphocytes are very rare. To overcome this problem, we investigated the requirements for generating IgE-secreting human hybridomas using in vitro immunization of peripheral blood lymphocytes. First, culture conditions were optimized for IgE production by a combination of the immunomodulatory mediators interleukin-2, interleukin-4, interleukin-6, and muramyl dipeptide. Second, the addition of mite antigen to the cultures resulted in an increased production of antigen-specific IgE as well as antigen-specific IgG and IgM. When activated lymphocytes in these cultures were fused with Burkitt lymphoma cells, ICLU-B, antigen-specific IgE-secreting hybridomas were obtained with high efficiency. These results demonstrate that our culture and in vitro immunization system for human peripheral blood lymphocytes is useful for obtaining antigen-specific IgE.