髓母细胞瘤（MB）是最常见的儿童脑肿瘤。尽管当前的治疗策略改善了患者的生存率，但由于后遗症和复发风险，这些患者的生活质量仍然很差。另一种替代方案，或者除了当前标准治疗之外，可以考虑免疫疗法，例如自然杀伤细胞（NK）。 NK 细胞是具有细胞毒性的先天淋巴细胞，在癌症免疫监视中发挥着重要作用。迄今为止，NK细胞的细胞毒性机制，特别是细胞接触区域的粘附、接合、细胞毒性颗粒极化、二维和三维空间中穿孔素和颗粒酶的释放以及体内治疗效果等步骤尚未得到精确描述。使用共聚焦显微镜进行接合、Elispot进行脱颗粒、流式细胞术以及针对靶细胞坏死和裂解以及细胞因子阵列释放的介质的发光测定来探索NK细胞毒性针对三种MB细胞系的每个步骤，然后在3D球体模型中进行确认。用 NK 细胞治疗髓母细胞瘤异种移植小鼠。通过流式细胞术评估它们的持久性，并确定它们对肿瘤生长和存活的功效。此外，还评估了它们对肿瘤转录组的影响。NK 细胞显示出与 MB 靶细胞缀合的不同亲和力，具体取决于其亚组和细胞因子激活。 NK 和 MB 细胞共培养期间分泌的趋化因子主要与血管生成和免疫细胞招募相关。在 2D 和 3D 共培养模型中，NK 细胞的细胞毒性会诱导 MB 细胞死亡。 NK 细胞通过调节 MB 细胞转录组在人类 MB 小鼠模型中引发炎症反应。我们的研究证实 NK 细胞对 MB 细胞具有体外和体内细胞毒活性，并且对免疫疗法的发展具有重要意义。© 2024 Gauthier等人。

Medulloblastoma (MB) is the most prevalent paediatric brain tumour. Despite improvements in patient survival with current treatment strategies, the quality of life of these patients remains poor owing to the sequelae and relapse risk. An alternative, or, in addition to the current standard treatment, could be considered immunotherapy, such as Natural Killer cells (NK). NK cells are cytotoxic innate lymphoid cells that play a major role in cancer immunosurveillance. To date, the mechanism of cytotoxicity of NK cells, especially regarding the steps of adhesion, conjugation, cytotoxic granule polarisation in the cell contact area, perforin and granzyme release in two and three dimensions, and therapeutic efficacy in vivo have not been precisely described.Each step of NK cytotoxicity against the three MB cell lines was explored using confocal microscopy for conjugation, Elispot for degranulation, flow cytometry, and luminescence assays for target cell necrosis and lysis and mediators released by cytokine array, and then confirmed in a 3D spheroid model. Medulloblastoma-xenografted mice were treated with NK cells. Their persistence was evaluated by flow cytometry, and their efficacy in tumour growth and survival was determined. In addition, their effects on the tumour transcriptome were evaluated.NK cells showed variable affinities for conjugation with MB target cells depending on their subgroup and cytokine activation. Chemokines secreted during NK and MB cell co-culture are mainly associated with angiogenesis and immune cell recruitment. NK cell cytotoxicity induces MB cell death in both 2D and 3D co-culture models. NK cells initiated an inflammatory response in a human MB murine model by modulating the MB cell transcriptome.Our study confirmed that NK cells possess both in vitro and in vivo cytotoxic activity against MB cells and are of interest for the development of immunotherapy.© 2024 Gauthier et al.