HUMAN IGE PRODUCTION IN HU-PBL-SCID MICE INJECTED WITH BIRCH POLLEN AND DIESEL EXHAUST PARTICLES

Mice with severe combined immunodeficiency were transplanted with huma n peripheral blood lymphocytes (hu-PBL-SCID mice). The response to imm unisation with birch pollen was used to study possible effects of dies el exhaust particles (DEP) and aluminium hydroxide (Al(OH)(3)) on huma n IgE production in this human in vivo model. The adjuvants were well tolerated, as determined by the number of human cells in the peritonea l cavity at the end of the experiments. Total and birch pollen-specifi c IgE was detected in 76 and 41% of the mice, respectively. In the pre sent experiments where the mice were stimulated early with birch polle n, a doubling in percentage of hu-PBL-SCID mice with production of spe cific IgE was observed, as compared to later stimulation used in previ ous experiments. Although a tendency to higher total IgE levels was ob served after treatment with DEP, no statistically significant adjuvant effect of DEP or Al(OH)(3) could be demonstrated. Electron microscopy analysis after immunogold labelling showed that the major birch polle n allergen Bet v I was released from the pollen grains and adsorbed to the surface of the DEP. Early stimulation with allergen appears to be important for optimal production of specific IgE in the hu-PBL-SCID m odel. However, our results show that further improvements are needed i n order to demonstrate the expected effects from adjuvants and environ mental pollutants. (C) 1998 Elsevier Science Ireland Ltd. All rights r eserved.