高效扩增和活化自然杀伤细胞并对多发性骨髓瘤细胞有特异性杀伤作用

Expansion and activation of natural killer cells with specific cytotoxicity against multiple myeloma

目的探讨辐照后的基因修饰的表达膜结合白细胞介素(IL)-15和4-1BB(CD137)配体的K562细胞株对扩增和活化健康人自然杀伤(NK)细胞的影响。方法 6名健康志愿者的外周血单个核细胞与辐照后的基因修饰的K562细胞株混合培养14d后,采用流式细胞仪分析和51铬释放法研究细胞的扩增情况和NK细胞的功能。结果本混合培养实验体系能有效地特异性扩增NK细胞(176.2±63.1)倍,而没有大量扩增T淋巴细胞[扩增倍数为(2.1±2.3)倍]和其他细胞。在效应细胞与靶细胞的比例为10∶1时,扩增后的NK细胞对U266细胞株的平均杀伤率为(73.6±11.2)%,显著高于扩增前的(30.1±9.7)%(P<0.01)。结论基因修饰的K562细胞株能刺激NK细胞高效扩增,扩增后的NK细胞杀伤U266细胞的作用显著增强,扩增的NK细胞将有可能用于骨髓瘤的免疫治疗。

Objective Natural killer （NK） cells appear to play a crucial role in controlling and/or eradicating some human haematopoietic tumors, including multiple myeloma. This study is to investigate the effects of co-incubation with irradiated K562 cells transfected with 4-1BBL and membrane-bound IL15 （K562 transfectants） can influence the expansion and activation of NK cells from healthy donors. Methods The peripheral blood mononuclear cells of 6 healthy individuals were co-cultured with irradiated K562 cell 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 and specifically expand NK cells （by a mean of [176.2±63.1] folds）, without expanding T cells （by [2.1±2.3] folds）and other cells. The expanded NK cells killed U266 MM cells avidly as shown by 51Cr-release assays. The mean cytotoxic rate of expanded NK cells against U266 cells was （73.6±11.2）% at an E：T ratio of 10：1 compared to （30.1±9.7）% of non-expanded NK cells. Conclusion K562 transfectants can stimulate vigorous expansion of NK cells, and the expanded NK cells had an enhanced cytotoxic effect against U266 MM cells. Expanded/activated NK cells may be used for immunotherapy of myeloma.