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Regulation of IgE response by employing recombinant IgE-binding factor

利用重组 IgE 结合因子调节 IgE 反应

基本信息

批准号：
62570213
负责人：
SUEMURA Masaki
金额：
$ 1.47万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62570213/
关键词：
Fc receptor II CD23, IgE IgE 即時型アレルギー好酸球好塩基球 BSF-1 IL4

项目摘要

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.

为了分析可溶性Fc受体II（Fc RII/CD 23）的作用，尝试生产重组可溶性Fc RII作为分泌蛋白。制备了几种含有可溶性受体序列的质粒构建体。只有含有编码IL-6信号肽序列和Fc RII可溶性部分的嵌合基因才能在非洲爪蟾卵母细胞和CHO细胞中表达，导致可溶性FC RII的分泌。神经氨酸酶处理降低了产物的分子量，表明可溶性受体可能是O-糖基化的。此外，该重组产物以及来源于人B细胞系的天然可溶性受体可结合人IgE和两种不同的单克隆抗Fc RII抗体。然而，重组可溶性Fc RII不显示任何B细胞生长促进活性。随后，可溶性Fc RII在IgE介导的超敏反应的效应相的功能进行了研究。可溶性Fc II以剂量依赖性方式抑制Fc RII^+单核细胞系U937和嗜酸性细胞系EoL-3的IgE玫瑰花结形成（在存在30 μ g/ml可溶性Fc II的情况下，60-70%的IgE玫瑰花结形成被抑制）。可溶性Fc Ⅱ也能抑制Fc RII介导的活化巨噬细胞产生O_2 ·。此外，可溶性Fc RII竞争性抑制IgE与嗜碱性粒细胞的结合，500 μ g/ml的可溶性Fc RII显示60-85%的抑制。这些结果表明，可溶性Fc RII可以调节IgE介导的超敏反应的效应相。可溶性Fc RII抑制组胺从碱性粒细胞释放的能力正在研究中。