膜表达IL-21的饲养层细胞对NK细胞体外扩增的影响

In Vitro Amplification of NK Cells from Feeder Layer Cells Expressing IL-21

目的:探究膜表达IL-21的饲养层细胞对NK细胞体外扩增的影响。方法:通过电转法构建膜表达IL-21的K562稳转细胞系,细胞灭活后与NK细胞共培养,观察NK细胞增殖情况。通过乳酸脱氢酶(LDH)和干扰素-γ(IFN-γ)释放实验检测扩增获得的NK细胞体外杀伤功能。构建NOD/SCID小鼠异种移植肠癌肿瘤模型,设置空白对照组、NK细胞组和扩增NK细胞组,检测扩增NK细胞体内肿瘤杀伤功能。结果:通过电转法成功构建了膜表达IL-21的K562细胞。与膜表达IL-21的K562细胞共培养17 d后,NK细胞的扩增倍数可达700倍,与对照组相比扩增能力明显增强(P<0.001)。体外肿瘤细胞杀伤实验检测结果显示,NK细胞和扩增后的NK细胞对肿瘤细胞的杀伤作用无明显差异,对小鼠体内肿瘤的杀伤效果也无明显差异。结论:膜表达IL-21的K562细胞可显著增强NK细胞的体外扩增能力,但不影响NK细胞的体内外杀伤功能,可用于后续NK细胞的体外规模化扩增。

Objective:To investigate the effect of feeder layer cells expressing interleukin(IL)-21 on the amplification of NK cells in vitro.Methods:The K562 cell line with IL-21 expression on its membrane was constructed by electroporation,and co-cultured with NK cells after inactivation.The proliferation of NK cells was observed.The killing function of the amplified NK cells in vitro was evaluated by the lactate dehydrogenase(LDH)and interferon-γ(IFN-γ)release assay.A colorectal cancer xenograft model|in NOD/SCID mice was established,and a blank control group,a NK cell group and an amplified NK cell group were set up to detect the tumor killing effect of amplified NK cells in vivo.Results:K562 cells expressing IL-21 on the membrane were successfully constructed by electroporation.After co-culturing with K562 cells expressing IL-21 on the membrane for 17 days,the NK cells increased to 700 times,which showed an enhanced amplification ability compared with control group(P<0.001).In the tumor cell klling experiment in vitro,there was no significant difference in the killing activity on tumor cells between NK cells and amplified NK cells,and there was also no significant difference in mice in vivo.Conclusion:K562 cells expressing IL-21 on the membrane can significantly increase the amplification ability of NK cells in vitro,but do not affect the killing function of NK cells in vitro and in vito.It can be used for the subsequent large scale production of NK cells in vitro.