BACKGROUND Cord Blood (CB) has been considered a promising source of natural killer (NK) cells for cellular immunotherapy. However, it is difficult to expand the large numbers of highly pure NK cells from CB without cell sorting and feeder cells/multiple cytokines. In this study, we try to develop a simple, safe and economical method for ex vivo expansion and purification of NK cells from CB without cell sorting and feeder cells/multiple cytokines. RESULTS The large numbers (mean: 1.59 × 1010) of highly pure (≥90%) NK cells from CB could be obtained through interleukin-2, group A streptococcus and zoledronate stimulation of mononuclear cells using the 21-day culture approach. When compared to resting NK cells, expanded NK cells were a higher expression of activating receptors CD16, NKG2D, NKp30, NKp44, NKp46 and activating markers CD62L and CD69, while the inhibitory receptors, CD158a and CD158b remained largely unchanged. In addition, these cells showed a higher concentration of IFN-γ, TNF-α and GM-CSF secretion and cytotoxicity to K562 cells and acute myeloid leukemia targets than resting NK cells. CONCLUSION We develop a simple, safe and economical method to obtain high yield, purity, and functionality NK cells from CB without cell sorting and feeder cells/multiple cytokines.

中文翻译：

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一种从脐带血体外制备天然杀伤细胞的简单方法。

背景技术脐带血（CB）已被认为是用于细胞免疫疗法的天然杀伤（NK）细胞的有希望的来源。但是，很难在不进行细胞分选和饲养细胞/多种细胞因子的情况下，从CB扩增出大量的高纯度NK细胞。在这项研究中，我们尝试开发一种简单，安全和经济的方法，用于从CB体外扩增和纯化NK细胞，而无需进行细胞分选和饲养细胞/多种细胞因子。结果通过使用白细胞介素-2，A组链球菌和唑来膦酸盐刺激单核细胞，可以使用21天的培养方法从CB中获得大量（平均：1.59×1010）高纯度（≥90％）NK细胞。与静止的NK细胞相比，扩增的NK细胞的活化受体CD16，NKG2D，NKp30，NKp44，NKp46和活化标记CD62L和CD69的表达更高，而抑制性受体CD158a和CD158b基本上保持不变。此外，与静息NK细胞相比，这些细胞显示出更高浓度的IFN-γ，TNF-α和GM-CSF分泌，并且对K562细胞和急性髓细胞白血病靶细胞具有细胞毒性。结论我们开发了一种简单，安全，经济的方法，可从CB获得高产率，纯度和功能性的NK细胞，而无需进行细胞分选和饲养细胞/多种细胞因子。