Study on the Molecule That Plays Critical Role in Allergic Response.

在过敏反应中起关键作用的分子的研究。

• 批准号: 12670732
• 负责人: MORIO Tomohiro
• 金额: $ 2.18万
• 依托单位: TOKYO MEDICAL AND DENTAL UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670732/
• 关键词: Ku70; 80; class switch; Fcε receptor; gene regulation; CD95; IL-4R; CD40; DNA-PK; IL-4; CD23; translocation; IgE; Ku70; 80; class switch; Fcε receptor; gene regulation; CD95; IL-4R; CD40; DNA-PK; IL-4; CD23; translocation; IgE

Ku70/80 that associates with CD40 translocates into the nucleus when B cells are stimulated through IL-4R/CD40. The same stimulation also leads to maximal expression of low affinity receptor for IgE (CD23). These data suggest that Ku70/80 plays a role in the regulation of CD23 expression. We have generated two different dominant negative (DN) constructs for Ku80 as EGFP-fusion proteins, transfected them into DND-39 B cell line, and examined the effect on IL-4R/CD40-driven CD23 expression. One of the DN constructs that lacks C terminal Ku80 inhibited IL-4R/CD40-driven CD23 expression.We have employed reporter gene assay to know whether EBVRE functions as enhancer of CD23 expression. Our study has shown that the region encompassing the Ku binding site (EBVRE) shows enhancing effect when B cells were stimulated with IL-4 and anti-CD40. We could not, however, show that Ku70/80 actually occupies the region in EMSA assay. These results suggest that Ku70/80 regulates expression of CD23.We have started looking at the effect of Ku70/80 on CD40-driven CD95 (Fas) expression and has determined Ku-binding site in the promoter region of CD95.Another interest is the modification of Ku70/80 and its effect on the Ku70/80function. Our study indicated that stress response leads to degradation of Ku70/80 that is mediated by serine protease or ubiquitination of Ku70/80. We are now examining whether the degradation results in apoptosis of the cells or in cessation of allergic response.AID is reported to be important for Immunoglobulin class switch. We have sequenced AID from 16 cases of non-X-linked hyper-IgM syndrome and found mutation in 9 cases. We are now examining whether there is any physiological or functional interaction between Ku70/80 and AID.

当B细胞通过IL-4R/CD40刺激B细胞时，与CD40相关联的Ku70/80会易位。相同的刺激也导致低亲和力受体对IgE的最大表达（CD23）。这些数据表明KU70/80在CD23表达的调节中起作用。我们已经将KU80的两个不同的主要负（DN）构建体作为EGFP融合蛋白，将其转染到DND-39 B细胞系中，并检查了对IL-4R/CD40驱动CD23表达的影响。缺乏C末端KU80的DN构建体抑制了IL-4R/CD40驱动的CD23表达。我们采用了记者基因测定法，以了解EBVRE是否作为CD23表达的增强子。我们的研究表明，当用IL-4和抗CD40刺激B细胞时，包含KU结合位点（EBVRE）的区域显示出增强的效果。但是，我们不能证明KU70/80实际上占据了EMSA分析区域。这些结果表明，KU70/80调节CD23的表达3.我们已经开始研究KU70/80对CD40驱动的CD95（FAS）表达的影响，并确定了CD95的启动子区域中的Ku结合位点。其他兴趣是Ku70/80的修饰及其对KU70/80/80/80/80 Funuction的影响。我们的研究表明，应力反应会导致丝氨酸蛋白酶或KU70/80的泛素化介导的KU70/80的降解。现在，我们正在研究降解是否导致细胞凋亡或停止过敏反应。AID据报道对于免疫球蛋白类转换非常重要。我们已经从16例非X连接的高IGM综合征中进行了测序，并在9例中发现了突变。我们现在正在研究KU70/80和AID之间是否存在任何生理或功能相互作用。