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Remodeling of cell surface oligosaccharides by introduction of glycogenes and its application

糖原引入对细胞表面寡糖的重塑及其应用

基本信息

批准号：
08557015
负责人：
TANIGUCHI Naoyuki
金额：
$ 11.33万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08557015/
关键词：
glycosyltransferase glycoprotein glycogene digosaccharide remodeling gnt3 糖鎖肝癌遺伝子発現

项目摘要

N-Acetylglucosaminyltransferase-III (GnT-III) catalyzes the formation of bisecting N-acetylglucosamine (GlcNAc) in the biosynthesis of N-linked oligosaccharides. To examine the effect of biosecting GlcNAc on the natural killer (NK) cytotoxicity, the GnT-III gene was introduced into NK-sensitive K562 cells that have no detectable GnTIII activity. Introduction of the gene resulted in complete blockage of the NK cytotoxicity against the transfected cells and also in a decrease of the binding of the effector cells to the target cells. After s.c. injection into nude mice, GnT-III-transfectants produced spleen colonization, although no spleen lesions were formed by control cells. In nude mice depleted of NK cells by anti-asialo GM1 antibody, both transfectants and controls yielded spleen colonization equally. These results indicate that K562 cells expressing GnT-III are resistant to NK cytotoxicity, resulting in spleen colonization in nude mice.The functional consequence of the sugar chain remodeling was examined in rat pheochromocytoma (PC12) cells by transfection of GnT-III gene. Nerve growth factor (NGF) stimulates neurite outgrowth for differentiation in PC12 cells, and the stimulation is mediated by a glycoprotein receptor for NGF,Trk. Transfection of GnT-III gene lead to loss of changes in morphology and growth rate upon NGF treatment. The detailed studies revealed that the altered structure of sugar chain in Trk impaired dimerization and phosphorylation of the receptor. These suggest that the function of glycoprotein receptor such as Trk is modified by alteration of N-glycan structure.

N-乙酰葡糖胺转移酶-III（GnT-III）在N-连接寡糖的生物合成中催化二等分N-乙酰葡糖胺（GlcNAc）的形成。为了检测生物切割GlcNAc对自然杀伤（NK）细胞毒性的影响，将GnT-III基因引入到没有可检测的GnTIII活性的NK敏感性K562细胞中。该基因的引入导致针对转染细胞的NK细胞毒性的完全阻断，并且还导致效应细胞与靶细胞的结合减少。皮下注射后注射到裸鼠中，GnT-III-转染子产生脾定殖，尽管对照细胞没有形成脾损伤。在通过抗去唾液酸GM 1抗体耗尽NK细胞的裸鼠中，转染子和对照均产生同等的脾定殖。这些结果表明，表达GnT-III的K562细胞对NK细胞毒性具有抵抗作用，导致裸鼠脾脏定植。通过转染GnT-III基因，检测了大鼠嗜铬细胞瘤（PC 12）细胞糖链重建的功能后果。神经生长因子（Nerve growth factor，NGF）刺激PC 12细胞中的神经突生长以用于分化，并且这种刺激由NGF的糖蛋白受体Trk介导。转染GnT-III基因后，NGF处理后的形态学和生长速率的变化消失。详细的研究表明，糖链结构的改变影响了受体的二聚化和磷酸化。这些表明糖蛋白受体如Trk的功能通过N-聚糖结构的改变而被修饰。