Ueno M, Yahara I, Kishi K
New Drug Research Laboratories, Shionogi & Co., Ltd., Futaba-cho 3-1-1, Osaka, Toyonaka, 561, Japan.
Fundam Appl Toxicol. 1997 Mar;36(1):39-46. doi: 10.1006/faat.1996.2280.
The side effects of recombinant human interleukin-2 (rhIL-2) in mice are considered to be mediated by lymphokine-activated killer (LAK) cells that have cytoplasmic granules and infiltrate into target organs. In cloned cytotoxic lymphocytes (CLs) including LAK cells in vitro, granule exocytosis is one of the mechanisms in target cell lysis, and hemolytic and BLT-serine esterase (BLT-SE) activities detected in the granules are important to the cytotoxicity of the CLs in vitro. However, no information is available on these activities of LAK granules in vivo in mice showing the side effects of rhIL-2. Therefore, the present study was designed to isolate the LAK granules from the homogenate of LAK cell-rich subcutaneous tissue in mice treated with continuous infusion of a dose of rhIL-2 that induces known toxicity. High activities in hemolysis and BLT-SE were detected in Percoll fractions from the tissue homogenate. Electron microscopic observation of these fractions revealed almost only LAK granules. These results indicate that hemolytic and BLT-SE activities are detectable in the LAK granules in vivo, suggesting that the cells have potency for cytotoxicity via their granules and are involved in the toxicity of rhIL-2 in mice. In addition, perforin, which has been identified as a hemolytic protein in CL granules in vitro, was not detected by immunoblotting in the granule fraction of the LAK cells in vivo, indicating that the hemolytic activity of the LAK granules in vivo is not due to perforin.
重组人白细胞介素-2（rhIL-2）在小鼠体内的副作用被认为是由具有细胞质颗粒并浸润到靶器官的淋巴因子激活的杀伤（LAK）细胞介导的。在体外包括LAK细胞在内的克隆细胞毒性淋巴细胞（CLs）中，颗粒胞吐作用是靶细胞裂解的机制之一，并且在颗粒中检测到的溶血和BLT-丝氨酸酯酶（BLT-SE）活性对CLs在体外的细胞毒性很重要。然而，关于显示rhIL-2副作用的小鼠体内LAK颗粒的这些活性尚无信息。因此，本研究旨在从连续输注诱导已知毒性剂量的rhIL-2的小鼠富含LAK细胞的皮下组织匀浆中分离LAK颗粒。在组织匀浆的Percoll组分中检测到高溶血活性和BLT-SE活性。对这些组分的电子显微镜观察显示几乎只有LAK颗粒。这些结果表明在体内LAK颗粒中可检测到溶血和BLT-SE活性，提示这些细胞通过其颗粒具有细胞毒性潜力，并参与rhIL-2在小鼠体内的毒性作用。此外，在体外已被鉴定为CL颗粒中溶血蛋白的穿孔素，在体内LAK细胞的颗粒组分中通过免疫印迹未检测到，表明体内LAK颗粒的溶血活性不是由穿孔素引起的。
