Lim Dong-Pyo, Jang Youn-Young, Kim Seokho, Koh Sang Seok, Lee Je-Jung, Kim Ju-Sun, Thi Phan Minh-Trang, Shin Dong-Jun, Shin Myung-Geun, Lee Seung-Hwan, Yoon Meesun, Kim Sang-Ki, Yoon Jung-Han, Park Min-Ho, Cho Duck
Department of Surgery, Chonnam National University Medical School, Gwangju, Korea.
Research Center for Cancer Immunotherapy, Chonnam National University, Hwasun Hospital, Jeollanam-do, Korea.
Cytotherapy. 2014 Oct;16(10):1419-30. doi: 10.1016/j.jcyt.2014.04.008. Epub 2014 Jun 18.
Interleukin-21 (IL-21) can enhance the effector function of natural killer (NK) cells but also limits their proliferation when continuously combined with IL-2/IL-15. Paradoxically, membrane-bound (mb)-IL-21 has been shown to improve human NK cell proliferation when cultured with IL-2/mb-IL-15. To clarify the role of IL-21, we investigated the effect of the timing of IL-21 addition to NK cell culture.
IL-2/IL-15-activated NK cells were additionally treated with IL-21 according to the following schedules; (i) control (without IL-21); (ii) first week (day 0 to day 7); (iii) intermittent (the first 3 days of each week for 7 weeks); (iv) after 1 week (day 8 to day 14); and (v) continuous (day 0 to day 49). The expression of NK receptors, granzyme B, perforin, CD107a, interferon-γ, telomere length and NK cell death were measured by flow cytometry.
Compared with the control (2004.2-fold; n = 10 healthy donors) and intermittent groups (2063.9-fold), a strong proliferative response of the NK cells on day 42 was identified in the "first week" group (3743.8-fold) (P < 0.05). NK cells treated with IL-21 in the "first week" group showed cytotoxicity similar to that in control cells. On day 28, there was a significant increase in cytotoxicity of "first week" NK cells that received IL-21 treatment for an additional 2 days compared with the "first week" NK cells (P < 0.05).
These data suggest that controlling temporal exposure of IL-21 during NK cell proliferation can be a critical consideration to improve the yields and cytotoxicity of NK cells.
白细胞介素-21（IL-21）可增强自然杀伤（NK）细胞的效应功能，但当与IL-2/IL-15持续联合使用时，也会限制其增殖。矛盾的是，已证明膜结合型（mb）-IL-21与IL-2/mb-IL-15共同培养时可促进人NK细胞增殖。为阐明IL-21的作用，我们研究了在NK细胞培养中添加IL-21的时间点的影响。
根据以下方案，用IL-21对经IL-2/IL-15激活的NK细胞进行额外处理；（i）对照组（无IL-21）；（ii）第一周（第0天至第7天）；（iii）间歇性（每周的前3天，共7周）；（iv）1周后（第8天至第14天）；以及（v）持续（第0天至第49天）。通过流式细胞术检测NK受体、颗粒酶B、穿孔素、CD107a、干扰素-γ、端粒长度和NK细胞死亡情况。
与对照组（2004.2倍；n = 10名健康供体）和间歇性组（2063.9倍）相比，在“第一周”组（3743.8倍）中，第42天时NK细胞出现强烈的增殖反应（P < 0.05）。“第一周”组中用IL-21处理的NK细胞显示出与对照细胞相似的细胞毒性。在第28天，与“第一周”的NK细胞相比，额外接受2天IL-21处理的“第一周”NK细胞的细胞毒性显著增加（P < 0.05）。
这些数据表明，在NK细胞增殖过程中控制IL-21的时间暴露可能是提高NK细胞产量和细胞毒性的关键考虑因素。
