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A study on specific intervention of allergic reaction

过敏反应特异性干预研究

基本信息

批准号：
07557033
负责人：
RA Chisei
金额：
$ 7.68万
依托单位：
Juntendo University School of Medicine, Department of Immunology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

1.We established a mouse model for IgE-mediated allergy by transplanting a IgE-producing hybridoma under the back skin. We analyzed allergic inflammation induced by IgE in this mouse model and confirmed this allergic inflammation was prevented by soluble human FcepsilonRIalpha ectodomain generated by gene-engineering.2.We established mouse monoclonal antibodies which recognize human FcepsilonRIalpha ectodomain. Of these antibodies we picked up the one (CRA2) that strongly inhibits IgE binding to FcepsilonRI and tried to humanize this CRA2by CDR-grafting for a specific anti-allergic reagent. The humanized CRA2 (hu CRA2) was as active as the original mouse CRA2 (mo CRA2) and the Fab fragment of hu CRA2 inhibited IgE binding to and histamine release from human basophils. In in vivo experiments with rhesus monkeys, the hu CRA2 exhibited almost no antigenicity and efficiently suppressed allergic inflammation induced by IgE.We are now trying to increase the affinity of this Ab to FcepsilonRI by amino-acid exchange and to develop a specific anti-allergic reagent.3.We have been performing screening of a variety of substances which can inhibit IgE binding to FcepsilonRI and found out several peomising substances. We are now trying to define the chemical structures of these substances.4.In order to clarify tertiary structure of the IgE binding site on the FcepsilonRIalpha, we have tried to crystalize the human FcepsilonRIalpha ectodomain and succeeded in generating a partial crystal. Still now we are trying to produce a complete crystal of the FcepsilonRIalpha for X-ray crystallography.

1.我们通过将产生IgE的杂交瘤移植到背部皮肤下，建立了IgE介导的过敏小鼠模型。我们在该小鼠模型中分析了IgE诱导的过敏性炎症，并证实通过基因工程产生的可溶性人FcepsilonRIalpha胞外域可以预防这种过敏性炎症。2.我们建立了识别人FcepsilonRIalpha胞外域的小鼠单克隆抗体。在这些抗体中，我们挑选了一种强烈抑制 IgE 与 FcepsilonRI 结合的抗体 (CRA2)，并尝试通过 CDR 移植将这种 CRA2 人源化为特定的抗过敏试剂。人源化 CRA2 (hu CRA2) 与原始小鼠 CRA2 (mo CRA2) 一样活跃，hu CRA2 的 Fab 片段抑制 IgE 与人嗜碱性粒细胞的结合以及组胺从人嗜碱性粒细胞中的释放。在恒河猴体内实验中，hu CRA2几乎没有抗原性，能够有效抑制IgE引起的过敏性炎症。我们现在正在尝试通过氨基酸交换的方式增加该抗体与FcepsilonRI的亲和力，开发特异性抗过敏试剂。 3.我们一直在筛选多种可以抑制IgE与FcepsilonRI结合的物质。 FcepsilonRI并发现了几种镇静物质。我们现在正在尝试定义这些物质的化学结构。4.为了阐明FcepsilonRIalpha上IgE结合位点的三级结构，我们尝试对人FcepsilonRIalpha胞外域进行结晶，并成功生成了部分晶体。现在我们仍在尝试生产用于 X 射线晶体学的 FcepsilonRIalpha 完整晶体。