Studies on the mechanism of Cytotoxic T-lymphocyte (CTL)-mediated muscle breakdown

细胞毒性T淋巴细胞（CTL）介导的肌肉破坏机制研究

• 批准号: 62570123
• 负责人: ISHIURA Shoichi
• 金额: $ 1.34万
• 依托单位: National Institute of Neuroscience, NCNP
• 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-62570123/
• 关键词: T-lymphocyte; Cytotoxicity; Myopathy; Perforin; Protease; Killer lymphocyte; CTL

The mechanism by Which structural proteins in myopathic muscle are degraded is not fully understood. This work focused on the killing molecules in T-lymphocytes from the viewpoint of their functions. During 2 years of research project, we found the following:1) Cytotoxic granules in cytotoxic T-lymphocytes (CTL) contain two distinct lytic molecules, perforin and serine esterase (SE). Perforin, which is released after signalling by a receptor on the CTL membrane, first binds to the target cell membrane and subsequently forms functional pore on the same membrane. These processes require Ca^<2+>ions. Heparin and other acid mucopolysaccharides only enhanced the pore-forming lytic process.2) We found that localization of SE is different from that of perforin in CTL cells. SE did not digest myosin, whereas other cytoplasmic protease digested it. Suggesting that SE is not directly involved in CTL-mddiated protein degradation.3) We isolated and purified two novel proteolytic enzymes, one is a high-molecular-mass multicatalytic proteinase, ingensin, and the other cystine aminopeptidase. Ingensin was shown to be involved in ATP-dependent proteolysis.

肌病肌肉中结构蛋白降解的机制还不完全清楚。这项工作从功能的角度重点关注T淋巴细胞中的杀伤分子。经过2年的研究，我们发现：1）细胞毒性T淋巴细胞（CTL）中的细胞毒颗粒含有两种不同的裂解分子：穿孔素和丝氨酸酯酶（SE）。在CTL膜上的受体发出信号后释放的穿孔蛋白首先与靶细胞膜结合，随后在同一膜上形成功能孔。这些过程需要Ca^2+离子。肝素和其他酸性粘多糖只促进孔形成的溶解过程。2）我们发现SE和穿孔素在CTL细胞中的定位不同。SE不消化肌球蛋白，而其他胞质蛋白酶消化肌球蛋白，表明SE不直接参与CTL介导的蛋白质降解。3）我们分离纯化了两种新的蛋白水解酶，一种是高分子量多催化蛋白酶ingensin，另一种是胱氨酸氨肽酶。研究表明，Ingensin参与ATP依赖性蛋白水解。

项目成果

S.Ishiura.: J.Biochem.103. 11-13 (1988)

S.Ishiura.：J.Biochem.103。

M. Yamamoto: "Chloride-activated cystine aminopeptidase. A new enzyme in human skeletal muscle." Biomed. Res.9. 11-19 (1988)

M. Yamamoto：“氯化物激活的胱氨酸氨基肽酶。人类骨骼肌中的一种新酶。”

S.Ishiura: J.Biochem.102. 9-12 (1987)

S.Ishiura：J.Biochem.102。

S. Ishiura: "Isolation of a Ca-dependent erythrolytic protein (perforin) from cytotoxic T-lymphocytes." J. Biochem.102. 9-12 (1987)

S. Ishiura：“从细胞毒性 T 淋巴细胞中分离出 Ca 依赖性溶红蛋白（穿孔素）。”

T. Tsukahara: "An "ATP-dependent protease" and ingensin in K562 cells." Eur. J. Biochem.177. 261-266 (1988)

T. Tsukahara：“K562 细胞中的一种“ATP 依赖性蛋白酶”和 ingensin。”