CAJ | 학술논문

　　目的通过体外扩增人NK细胞的方法，探讨扩增后NK细胞对K562和HL60白血病细胞株的体外杀伤作用及机制。方法抽取5例健康志愿者外周血，分离单个核细胞（PBMC），与基因修饰K562细胞共同培养，采用流式细胞仪检测NK细胞的表型，铬51释放法测定NK细胞对白血病细胞的杀伤率。结果基因修饰K562细胞在体外刺激NK细胞扩增202倍；扩增后NK细胞对白血病细胞K562、HL60的杀伤率分别为77.1%、61.2%（效/靶比为8∶1），扩增前NK细胞对K562、HL60杀伤率分别为39.0%、35.4%；扩增后NK细胞表面活化受体NKG2D、NKp30和NKp44表达增强；这些活化受体特异抗体能部分抑制扩增后NK细胞的抗白血病作用。结论基因修饰K562细胞刺激NK细胞有效扩增，扩增后NK细胞杀伤白血病细胞作用明显增强，扩增后NK细胞表面部分活化受体上调可能为扩增后NK细胞抑制白血病作用增强的分子机制，NK细胞治疗在白血病中有潜在的应用前景。
　　목적통과체외확증인NK세포적방법，탐토확증후NK세포대K562화HL60백혈병세포주적체외살상작용급궤제。방법추취5례건강지원자외주혈，분리단개핵세포（PBMC），여기인수식K562세포공동배양，채용류식세포의검측NK세포적표형，락51석방법측정NK세포대백혈병세포적살상솔。결과기인수식K562세포재체외자격NK세포확증202배；확증후NK세포대백혈병세포K562、HL60적살상솔분별위77.1%、61.2%（효/파비위8∶1），확증전NK세포대K562、HL60살상솔분별위39.0%、35.4%；확증후NK세포표면활화수체NKG2D、NKp30화NKp44표체증강；저사활화수체특이항체능부분억제확증후NK세포적항백혈병작용。결론기인수식K562세포자격NK세포유효확증，확증후NK세포살상백혈병세포작용명현증강，확증후NK세포표면부분활화수체상조가능위확증후NK세포억제백혈병작용증강적분자궤제，NK세포치료재백혈병중유잠재적응용전경。
Objective This study is to investigate the method for expansion of human NK cells in vitro. We also tested the role of expanded NK cells in killing of K562 and HL60 leukemia cells and its mechanism. Methods Peripheral blood mononucle-ar cells (PBMC) were isolated from peripheral blood donored by 5 healthy individuals. PBMC were co- cultured with irradiated genetic modified K562 cel transfectants for 14 days. The cultures were then analyzed for fold expansion and cytotoxicity by flow cytometry and 51Cr- release assays. Results This co- culture system could effectively expand NK cells (by a mean of 202 folds). The expanded NK cells killed K562 and HL60 cells avidly as shown by 51Cr- release assays. The mean cytotoxic rate of expanded NK cel s against leukemia cells was 77.1%(K562), 61.2%(HL60) at an E∶T ratio of 8∶1 compared to 39.0%(K562), 35.4% (HL60) of non- expanded NK cel s, respectively. There was no killing of auto- and al o- PBMC. We observed stronger ex-pression of activating receptor NKG2D, NKp30, NKp44 in expanded NK cel s than in non- expanded NK cells. These specific an-tibodies could partly inhibited the enhanced lysis of K562 cells by expanded NK cells. Conclusion K562 transfectants can stim-ulate vigorous expansion of NK cells, and the expanded NK cells had an enhanced cytotoxic effect against leukemia cells. Up- regulation of activating receptors on expanded NK cells may be the mechanisms of enhanced killing of leukemia cells by ex-panded NK cells. NK cell therapy may be used for immunotherapy of leukemia.