Establishment of human IgE system in severe combined immunodeficient mice with peripheral blood mononuclear cells from asthmatic children.

The frequency of allergic diseases, such as asthma, has increased rapidly during the past decade; however, the exact mechanisms have not been established. In this study we tried to establish an in vivo system to investigate immune regulation of allergic diseases by using severe combined immunodeficient (SCID) mice. Peripheral blood mononuclear cells isolated from asthmatic children or normal adults were injected into peritoneal cavities of SCID mice. Human IgG, IgA, IgM, and IgE could be detected in SCID mice reconstituted with human PBMCs (SCID-PBL-hu mice) 3 weeks later. Moreover, the mice injected with peripheral blood mononuclear cells from asthmatic children had much higher IgE levels than mice reconstituted with cells from normal adults. Phenotypic analysis of spleen cells and peritoneal exudate cells from SCID-PBL-hu mice demonstrated that human lymphocytes could survive in the peritoneal cavity and spleen for several months. After intraperitoneal immunization, mite-specific IgE antibodies could also be detected in SCID-PBL-hu mice. This study indicates that the human IgE system can be established in SCID mice and that this model can be used to study the regulation of IgE production and the immunopathogenesis of human allergic disease.