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Research on the B cell development using mutant mice generated through gene targeting.

使用通过基因靶向产生的突变小鼠进行 B 细胞发育研究。

基本信息

批准号：
04670291
负责人：
KITAMURA Daisuke
金额：
$ 1.41万
依托单位：
KYUSHU 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：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04670291/
关键词：
B cell development pre-B cell receptor lambda5 muM gene targeting HS1 Thnmice slslction apoptos 膜型mu鎖 lambda5 遺伝子再構成膜型μ鎖

项目摘要

Immunoglobuline(Ig) mu chain is expressed on the surface of pre-B cells as a receptor associated with Vpre-B and lambda5 proteins. To understand the physiological function of the pre-B cell receptor, the membrane exon of the mu chain gene and lambda5 gene were disrupted separately in embryonic stem cells by gene targeting, and through the transmission of these mutations into the mouse germ lines, the mutant mice, muMT and lambda5T, were generated. In the B cells from heterozygous muMT mice, muMT allele does not exclude the other heavy chain allele. Homozygous muMT mice lack B cells and B cell development is arrested at or before the stage of large pre-B cells. Similarly, B cell development is inhibited in homozygous lambda5T mice, although this inhibition is leaky, suggesting the presence of lambda5-independent pathway of the B cell development. L chain gene rearrangement occurs in the immature cells in these mutants to the same extent as those cells in normal mice, indicating the initiation of the L chain gene rearrangement is independent of the pre-B cell receptor.HS1 protein is one of the major substrates of Src-like protein tyrosine kinases and phosphorylated immediately after crosslinking of surface IgM(sIgM)on B cells. The HS1 is also tyrosine-phosphorylated upon the stimulation of T cell receptors(TCR). The HS1 deficient mice, which were generated through gene targeting, showed the impaired ability for thymic negative selection as well as the impaired apoptotic cell death of the B cells induced by the crosslinking of sIgM.This results clearly demonstrated that HS1 is a molecule involved in the signal transduction pathway toward apoptosis that is triggered the antigen receptors.

免疫球蛋白 (Ig) mu 链作为与 Vpre-B 和 lambda5 蛋白相关的受体在前 B 细胞表面表达。为了了解前B细胞受体的生理功能，通过基因打靶在胚胎干细胞中分别破坏mu链基因和lambda5基因的膜外显子，并通过将这些突变传递到小鼠种系中，产生了突变小鼠muMT和lambda5T。在来自杂合 muMT 小鼠的 B 细胞中，muMT 等位基因不排除其他重链等位基因。纯合 muMT 小鼠缺乏 B 细胞，B 细胞发育在大前 B 细胞阶段或之前停滞。类似地，纯合 lambda5T 小鼠中的 B 细胞发育受到抑制，尽管这种抑制是有漏洞的，这表明 B 细胞发育存在不依赖于 lambda5 的途径。这些突变体的未成熟细胞中发生L链基因重排的程度与正常小鼠的细胞相同，表明L链基因重排的启动不依赖于前B细胞受体。HS1蛋白是Src样蛋白酪氨酸激酶的主要底物之一，在B细胞表面IgM(sIgM)交联后立即磷酸化。 HS1 在 T 细胞受体 (TCR) 刺激下也会被酪氨酸磷酸化。通过基因打靶产生的 HS1 缺陷小鼠表现出胸腺阴性选择能力受损，以及 sIgM 交联诱导的 B 细胞凋亡细胞死亡受损。这一结果清楚地表明，HS1 是参与触发抗原受体的细胞凋亡信号转导途径的分子。