Regulation of IgE response by employing recombinant IgE-binding factor

In order to analyze the role of soluble Fc receptor II （Fc RII/CD23）， attempts were made to produce recombinant soluble Fc RII as a secretory protein。Several plasmid constructs containing soluble receptor sequence were prepared。只有化学基因含有序列编码IL-6信号肽和Fc RII的溶剂动力学才能在Xenopus Leavis ocytes和CHO细胞中表达，在溶剂FC RII的秘密中的结果。神经酰胺酶治疗减少了产品的MW，建议溶解受体可能是0-糖基化的。更进一步，这种重组产品很好地作为自然溶剂受体从人类B细胞线中衍生出人类IgE和两种不同的单克隆抗Fc RII抗体。However，再组合的可控性Fc RII没有显示任何B细胞生长促进活动。在IgE介导的高敏感性效应阶段的可控性Fc RII的功能已被研究。Soluble Fc II抑制了Fc RII^+单细胞系、U937和碘化细胞系、Eol-3的IgE-rosette形成，在一种依赖于剂量的时尚中（在30克/毫升的溶剂Fc II中，IgE-rosette形成不足60- 70%）。Soluble Fc II也是抑制的Fc RII-mediated O_2 ·通过nitro blue四氮唑ium（NBT）测试确定的激活宏的产品。更远、更稳定的Fc RII有效地抑制了IgE与碱性药物的结合，500克/毫升的溶剂Fc RII显示了60- 85%的抑制剂。这些结果表明，解决FCRII可能调节IgE介导的高敏感性效应阶段。解决FCRII的可能性，以抑制从丙烷中释放的组胺在调查中的作用。

In order to analyze the role of soluble Fc receptor II (Fc RII/CD23), attempts were made to produce recombinant soluble Fc RII as a secretory protein. Several plasmid constructs containing soluble receptor sequence were prepared. Only a chimeric gene containing the sequences encoding IL-6 signal peptide and the soluble moiety of Fc RII could be expressed in Xenopus leavis oocytes and CHO cells, resulting in the secretion of soluble FC RII. Neuraminidase treatment reduced the MW of the product, suggesting that soluble receptor might be 0-glycosylated. Furthermore, this recombinant product as well as natural soluble receptor derived from a human B cell line could bind both human IgE and two different monoclonal anti-Fc RII antibodies. However, the recombinant soluble Fc RII did not display any B cell growth promoting activity.Subsequently, the function of soluble Fc RII in effector phase of IgE-mediated hypersensitivity was studied. Soluble Fc II inhibited IgE-rosette formation of Fc RII^+ monocytic cell line, U937, and eosinophilic cell line, EoL-3, in a dose dependent fashion (in the presence of 30 g/ml soluble Fc II, 60-70% of IgE-rosette formation was suppressed). Soluble Fc II also inhibited Fc RII-mediated O_2 ・ production of activated macrophages as determined by nitro blue tetrazolium (NBT) test. furthermore, soluble Fc RII competitively inhibited the binding of IgE to basophils, and 500 g/ml of soluble Fc RII showed 60-85% inhibition. These results indicate that soluble Fc RII may regulate the effector phase of IgE-mediated hypersensitivity. The ability of soluble Fc RII to inhibit histamine release from basoplils is under investigation.