| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
Peripheral blood basophils express FcepsilonRI on the surface. The regulatory mechanism of its expression is, however, largely unknown. In particular, there has been no report regarding the FcepsilonRI expression on circulating basophils during childhood. In this study, we evaluated IgE binding and FcepsilonRI expression on basophil surface in neonates and in children of various age groups. Furthermore, the regulation of FcepsilonRI by monomeric IgE was examined. In addition, serum IgE concentration was determined by a sensitive ELISA assay using anti-IgE monoclonal antibodies. Basophil-bound IgE was significantly high among allergics than normal controls. The difference was more prominent among younger age groups. The surface-bound IgE correlated very well with serum IgE concentrations. The level increased rapidly around 100 ng/ml of IgE and it reached a plateau when serum IgE was higher than 300 ng/ml. IgE-binding cell was undetectable within neonatal cord blood. However, IgE binding was induced rapidly when the cells were incubated with excess monomeric IgE for short period. Longer incubation resulted in further potentiation of IgE binding. FcepsilonRI expression on basophil surface also correlated well with serum IgE.FcepsilonRI expression on neonatal basophils was relatively low, but the level was upregulated when these cells were incubated with IgE.The enhancement was dependent on de novo protein synthesis. Constitutive synthesis of FcepsilonRI mRNA synthesis was observed in neonatal blood and the level was not significantly increased after the addition of IgE,indicating that a mechanism other than mRNA transcription is involved in the regulation of surface IgE receptor expression.
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