多发性骨髓瘤患者自然杀伤细胞体外扩增及其抗自体骨髓瘤作用

目的探讨体外高效扩增多发性骨髓瘤(MM)患者自身自然杀伤细胞(NK细胞)的方法,研究扩增前和扩增后NK细胞对骨髓瘤细胞株U266和自体骨髓瘤细胞的杀伤作用。方法 10例MM患者的外周血单个核细胞与K562转基因细胞株在含不同浓度白细胞介素(IL)-2的培养液中共育14d,应用流式细胞仪,采用氚标记的胸腺嘧啶核苷(3H-TdR)掺入法和铬51释放法等方法,研究NK细胞的扩增情况、增殖能力、免疫表型和抗骨髓瘤作用。结果 300U/mLIL-2共培养体系扩增NK细胞的扩增倍数为196.4±12.8,扩增后NK细胞存活率>95%,IL-2能增强共培养体系中NK细胞的增殖能力。在效靶比为10∶1时,扩增后NK细胞对自体骨髓瘤细胞的平均杀伤率为(38.1±6.2)%,显著高于扩增前的(3.9±1.7)%(P<0.01)。结论 K562转基因细胞株能特异性刺激骨髓瘤患者NK细胞扩增,扩增后NK细胞抗自体骨髓瘤的作用显著增强,扩增并活化的NK细胞将有望作为临床治疗MM的免疫治疗方法。

Ex-vivo amplification of naturel killer cells from multiple myeloma patients and its autologous antitumor activity

Objective To explore the possibility of ex-vivo amplification of natural killer (NK) cells from multiple myeloma patients and investigate their cytotoxicity against U266 myeloma cell line and autologous tumor cells. Methods Mononuclear cells from the peripheral blood of 10 myeloma patients were co-cultrured with genetically-modified K562 cells in the media containing various concentrations of interleukin 2 (IL-2) for 14 d. Amplification, proliferation, phenotype and antitumor activity of NK cells were analyzed by flow cytometry, 3H-TdR incorporation and 51Cr release assay. Results NK cells from 300 U/mL IL-2 co-culture system increased by (196.4±12.8) fold with a high viability of >95%. IL-2 enhanced the proliferation of NK cells in the co-culture system. As the ratio of effector to target was 10∶1, (38.1±6.2)% of the targets were killed by the expanded NK cells, whereas unexpanded ones killed only (3.9±1.7)% of the targets (P<0.01). Conclusion Genetically-modified K562 cells can specifically stimulate the amplification of NK cells in multiple myeloma patients. The expanded NK cells can significantly increase the cytotoxicity against autologous myeloma cells. Based on these findings, we propose that autologous NK cells expanded ex vivo deserve further attention as a possible therapeutic strategy for multiple myeloma. (Shanghai Med J, 2012, 35: 415-419)