IGE BINDING AND CD38 EXPRESSION ON BASOPHIL SURFACE DURING INFANCY AND THEIR FUNCTIONAL RELEVANCE

外周血嗜碱性粒细胞在表面上表达FcepsilonRI。然而，其表达的调节机制在很大程度上是未知的。特别是，还没有关于儿童期循环嗜碱性粒细胞上FcephsilonRI表达的报道。在这项研究中，我们评估了IgE结合和FcepsilonRI表达的嗜碱性粒细胞表面的新生儿和不同年龄组的儿童。此外，检查了单体IgE对Fc ε RI的调节。此外，使用抗IgE单克隆抗体通过灵敏的ELISA测定法测定血清IgE浓度。嗜碱性粒细胞结合的IgE显着高于正常对照组过敏。在较年轻的年龄组中，这种差异更为突出。表面结合的IgE与血清IgE浓度相关性非常好。IgE水平在100 ng/ml左右迅速升高，当血清IgE高于300 ng/ml时达到平台。新生儿脐血中未检测到IgE结合细胞。然而，当细胞与过量的单体IgE孵育短时间时，IgE结合被迅速诱导。更长的孵育导致IgE结合的进一步增强。FcepsilonRI在嗜碱性粒细胞表面的表达也与血清IgE水平相关，新生儿嗜碱性粒细胞表面FcepsilonRI的表达相对较低，但当这些细胞与IgE共同孵育时，FcepsilonRI的表达水平上调，这种上调依赖于从头蛋白合成。在新生儿血液中观察到FcepsilonRI mRNA合成的组成型合成，并且在添加IgE后水平没有显著增加，表明除了mRNA转录之外的机制参与了表面IgE受体表达的调节。

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.