TOTAL AND BIRCH POLLEN-SPECIFIC HUMAN IGE IN MICE WITH SEVERE COMBINED IMMUNODEFICIENCY TRANSPLANTED WITH HUMAN PERIPHERAL-BLOOD LYMPHOCYTES - DONOR DEPENDENCE, SEASONAL-VARIATION AND IN-VIVO HALF-LIFE

Background: There is a need for animal in vivo models in the study of human allergy. The aim of the present experiments was to study product ion and catabolism of human IgE in mice with severe combined immunodef iciency transplanted with human peripheral blood lymphocytes (hu-PBL-S CID mice). Methods: Groups of SCID mice were transplanted intraperiton eally with hu-PBL from the same three donors in five experiments. Subg roups of transplanted mice were immunized with birch pollen. Productio n of human total and birch pollen-specific IgE in the hu-PBL-SCID mice was analyzed over a 7-week period. Results: Human IgE was detected in 93% of the hu-PBL-SCID mice, and the production showed reproducible d onor-dependent kinetics. Production of birch pollen-specific human IgE , however, was seen only in mice transplanted with cells from birch po llen-allergic donors. A greater proportion of the mice produced specif ic ISE when the experiment was started in, or some months after a birc h pollen season with high pollen counts. The half-lives of passively t ransferred human IgE were determined to be 24.0 and 23.4 h for total a nd birch pollen-specific ISE, respectively. Conclusions: This study de monstrates that human IgE production in hu-PBL-SCID mice is very repro ducible when the same donor is used several times. Specific IgE produc tion in recipient mice seems to require the use of cell donors with th e actual specific allergy, and is most readily obtained during or afte r a period of donor allergen exposure. The short half-lives found indi cate that hu-PBL-SCID mice have a high ongoing production of human IgE .