IL-18联合IL-2诱导NK92细胞的实验研究

Experimental study on anti-tumor activity of NK92 cells induced by interleukin-18 combined with interleukin-2

目的:探讨白细胞介素18(IL-18)联合白细胞介素2(IL-2)对自然杀伤细胞系NK92抗卵巢肿瘤作用的影响。方法:用不同浓度的IL-18联合IL-2(5 U/ml)体外诱导刺激NK92细胞,流式细胞仪检测细胞周期变化。乳酸脱氢酶释放试验观察刺激前后NK92细胞及培养上清对SKOV3体外生长的抑制作用。ELISA测定NK92细胞杀伤活性最大时IFN-γ、TNF-α含量。结果:IL-18(25 ng/ml)+IL-2(5 U/ml)刺激后的NK92细胞与对照组比较,S期细胞增多,G0/G1期减少(P<0.05)。效靶比为10∶1时,诱导后NK92细胞对SKOV3细胞作用4 h杀伤活性最高,IL-18+IL-2刺激前后的NK92细胞杀伤率分别为(42.3±4.82)%、(77.63±5.27)%。NK92培养上清36 h对SKOV3杀伤作用达到最高峰,刺激前后上清杀伤率分别为(21.2±3.49)%、(37.14±2.69)%。NK92细胞杀伤活性最大时,上清中IFN-γ、TNF-α水平明显升高(P<0.05)。结论:IL-18联合IL-2可提高NK92细胞的抗肿瘤活性,为临床应用NK92细胞免疫治疗卵巢肿瘤提供了实验依据。

Objective： To investigate the anti-tumor activity of NK92 cells induced by interleukin- 18 （ IL- 18） combined with interleukin-2（ IL-2）. Methods： NK92 cells were induced by IL-18 at different doses in combination with IL-2 （5 U/ml） in vitro, and then flowcytometry was used to observe the changes of cell cycle, LDH releasing test to examine NK92 cells and its supernatant mediated cytotoxic activity on the growth of ovarian carcinoma cell line in vitro, and enzyme-linked immunosorbent assay （ELISA） to qualify the IFN-γ and TNF-α levels in supematant when NK92 cells exhibited the highest cytotoxicity. Results： There was a statistical up-tendency in S phase proportion of NK92 cells after stimulated by IL-18（25 ng/ml） and IL-2（5 U/ml）, whereas a statistical down-tendency in G0/G1 phase proportions among normal control（ P 〈 0.05）. When the effector-to-target ratio was 10： 1, the NK92 cells exhibited the highest cytotoxicity on SKOV3 cells 4 hours later. Before and after being stimulated with IL-18 and IL-2, the cytotoxicity of NK92 cells was （42.3 ± 4.82） % and （77.63 ± 5.27） % respectively. After incubated with target cells for 36 hours, NK92 supematant exhibited the highest cytotoxicity on SKOV3 cell, and before and after stimulation, the cytotoxicity of NK92 supematant was （21.2 ± 3.49） % and （37.14 ± 2.69） % respectively. The levels of IFN-γ and TNF-α in the supematant were elevated significantly when NK92 cells exhibited the highest cytotoxicity on SKOV3 cells （P 〈 0.05）. Conclusion： IL-18 in combination with IL-2 may increase the anti-tumor activity of NK92, which provides the experimental basis for immunotherapy of ovarian tumor with NK92 cells.