Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei 112, Taiwan.
Department of Laboratory Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
Int J Mol Sci. 2018 Apr 4;19(4):1073. doi: 10.3390/ijms19041073.
Altered sialic acid processing that leads to upregulation of cell surface sialylation is recognized as a key change in malignant tissue glycosylation. This cancer-associated hypersialylation directly impacts the signaling interactions between tumor cells and their surrounding microenvironment, especially the interactions mediated by immune cell surface sialic acid-binding immunoglobulin-like lectins (Siglecs) to relay inhibitory signals for cytotoxicity. First, we obtained a Siglec-7 NK-92MI cell line, NK-92MI-S7N, by separating a group of Siglec-7 cell population from an eight-month-long-term NK-92MI in vitro culture by fluorescence-activated cell sorting (FACS). The effect of Siglec-7 loss on NK-92MI-S7N cells was characterized by the cell morphology, proliferation, and cytotoxic activity via FACS, MTS assay, cytotoxic assay, and natural killer (NK) degranulation assay. We found the expression levels of Siglec-7 in NK-92MI were negatively correlated with NK cytotoxicity against leukemia cells. This NK-92MI-S7N cell not only shared very similar phenotypes with its parental cells but also possessed a high and sustainable killing activity. Furthermore, this Siglec-7 NK line was unexpectedly capable of eliminating a NK-92MI-resistant leukemia cell, THP-1, through enhancing the effector-target interaction. In this study, a NK cell line with high and sustainable cytotoxicity was established and this cell may provide a potential application in NK-based treatment for leukemia patients.
糖基化是恶性组织中一种关键的变化，其特征为唾液酸加工改变，导致细胞表面唾液酸化上调。这种与癌症相关的高唾液酸化直接影响肿瘤细胞与其周围微环境之间的信号相互作用，特别是免疫细胞表面唾液酸结合免疫球蛋白样凝集素（Siglec）介导的相互作用，这些作用传递细胞毒性的抑制信号。首先，我们通过荧光激活细胞分选（FACS）从 NK-92MI 的八个月体外培养物中分离出一组 Siglec-7 细胞群，获得了 Siglec-7 NK-92MI 细胞系 NK-92MI-S7N。Siglec-7 缺失对 NK-92MI-S7N 细胞的影响通过 FACS、MTS 测定、细胞毒性测定和自然杀伤（NK）脱颗粒测定来表征细胞形态、增殖和细胞毒性活性。我们发现 NK-92MI 中的 Siglec-7 表达水平与 NK 对白血病细胞的细胞毒性呈负相关。这种 NK-92MI-S7N 细胞不仅与其亲本细胞具有非常相似的表型，而且具有高且可持续的杀伤活性。此外，这种 Siglec-7 NK 系出人意料地能够通过增强效应物-靶相互作用来消除 NK-92MI 耐药白血病细胞 THP-1。在这项研究中，建立了一种具有高且可持续细胞毒性的 NK 细胞系，该细胞系可能为基于 NK 的白血病患者治疗提供了一种潜在的应用。
