中文摘要：

目的为了研究表达白细胞介素-21（IL-21）对自然杀伤细胞（NK）细胞的扩增的数量、表型和功能的影响。方法以人外周血单个核细胞（PBMC）为扩增培养对象,实验组加入IL-21,在体外培养条件下使NK细胞大量的扩增。采用流式细胞仪检测NK细胞表型。NK细胞作用到K562细胞,对NK细胞的杀伤性进行功能分析,~（51）Cr释放实验检测NK细胞对K562细胞杀伤水平的影响。结果 IL-21加入到PBMC后,培养体系经过23 d的刺激后,IL-21诱导PBMC扩增,CD56＋CD16＋CD3-细胞数量比对照组增加了2.6倍,对照组CD56＋CD16＋CD3-细胞的纯度为26.5%±1.7%,实验组扩增后是73.9%±2.1%。细胞毒实验表明,在NK效应细胞：K562靶细胞为10∶1和20∶1时,实验组明显高于对照组。结论本方法以单纯的添加细胞因子IL-21的方法,能够实现NK细胞体外扩增,建立了更优化的NK细胞体外扩增方法,且扩增的NK细胞对K562细胞的杀伤活性较好。本实验对于NK的大量扩增和临床应用具有一点的指导价值。

英文摘要：

Objective In order to study the influence of different culture conditions on activity of nature killer cells （NK）,whether joining IL-21 cytokine or not. Methods Peripheral blood mononuclear cells （PBMC） were extracted from human peripheral blood,and then were explanted by IL-21 cytokine stimulated. The number of NK cells increased by IL-21 cytokine. Immunophenotypic analysis of NK cell surface markers was performed by flow cytometry （FCM）.~（51）Cr release assay was employed to measure the specific lysis skilling of NK cell target K562 cells.Results We have used IL-21 added into the PBMC,an average of 2. 6 fold expansion of CD3-CD56 ＋ CD16 ＋cells was observed after 23 day of co-culture system. The NK cells population could proliferate more 26. 5% ± 1.7% after expansion in PBMC before expansion by FCM. The cytotoxical activity of NK cells which was induced by IL-21 cytokine was the strongest than induced by IL-6 cytokine alone. The expanded NK cells lysed 73. 9% ± 2. 1% of K562 targets in a 10： 1 and 20： 1 effectors to target ratio. In this case,the NK cell induced by IL-21 against tumor cells was more lethal. Conclusions PBMC based in vitro expansion of natural killer cells was set up by IL-21 cytokine. The cytotoxicity of NK cells was the strongest induced by IL-21 cytokine treated. These results had important guiding significance for the NK large number of amplification and used in clinical.