Autonomous growth and increased cytotoxicity of natural killer cells expressing membrane-bound interleukin-15
Autonomous growth and increased cytotoxicity of natural killer cells expressing membrane-bound interleukin-15
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DOI：
10.1182/blood-2014-02-556837
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发表时间：
2014-08-14
期刊：
影响因子：
20.3
通讯作者：
Campana, Dario
中科院分区：
文献类型：
--
作者：
Imamura, Masaru;Shook, David;Campana, Dario
自然杀伤(NK)细胞的存活和细胞毒性需要细胞因子的支持。我们确定了非分泌型、膜结合型的白介素15(IL-15)的表达是否能够维持NK细胞的生长。我们将人IL15基因与编码CD8α跨膜区(MbIL15)的基因连接起来。逆转录病毒转导后，人NK细胞表面表达mBIL15，IL-15分泌很少。培养7天后，不加白介素2(IL-2)的mBIL15-NK细胞的存活率明显高于未转导的NK细胞(P<；.001，n=15)和表达非结合IL-15的NK细胞(P=0.025，n=9)；存活的mBIL15-NK细胞最长可达2个月。在免疫缺陷小鼠中，mBIL15-NK细胞在没有IL-2的情况下扩增，并且在所有被检查的组织(脑除外)中都能检测到，其数量远远高于模拟转导的NK细胞(P<；.001)。随着IL-2浓度的增加，细胞扩张率进一步增加。其主要作用机制为自分泌，激活IL-15信号和抗细胞凋亡信号。表达mBIL15的NK细胞在体外对白血病、淋巴瘤和实体瘤细胞有较高的杀伤活性，在异种移植模型中对白血病和肉瘤细胞有较高的杀伤活性。因此，mBIL15赋予NK细胞独立的生长能力，并增强其抗肿瘤能力。输注mBIL15-NK细胞将允许NK细胞治疗，而不会出现细胞因子注射的潜在不良反应。
Natural killer (NK) cell survival and, hence, cytotoxicity requires cytokine support. We determined whether expression of interleukin-15 (IL-15) in a nonsecretory, membrane-bound form could sustain NK cell growth. We linked the human IL15 gene to that encoding CD8 alpha transmembrane domain (mbIL15). After retroviral transduction, human NK cells expressed mbIL15 on the cell surface; IL-15 secretion was negligible. Survival of mbIL15-NK cells without interleukin-2 (IL-2) after 7-day culture was vastly superior to that of mock-transduced NK cells (P < .001, n = 15) and of NK cells expressing nonmembrane-bound IL-15 (P = .025, n=9); viable mbIL 15-NK cells were detectable for up to 2 months. In immunodeficient mice, mbIL15-NK cells expanded without IL-2 and were detectable in all tissues examined (except brain) in much higher numbers than mock-transduced NK cells (P < .001). Expansion further increased with IL-2. The primary mechanism of mbIL15 stimulation was autocrine; it activated IL-15 signaling and antiapoptotic signaling. NK cells expressing mbIL15 had higher cytotoxicity against leukemia, lymphoma, and solid tumor cells in vitro and against leukemia and sarcoma cells in xenograft models. Thus, mbIL15 confers independent growth to NK cells and enhances their antitumor capacity. Infusion of mbIL15-NK cells would allow NK cell therapy without the potential adverse effects of cytokine administration.