Purpose

Disialoganglioside GD₂ is expressed by glioblastoma multiforme (GBM) cells representing a promising target for anti-GD2 immunotherapeutic approaches. The aim of the present study was to investigate anti-tumor efficacy of the chimeric anti-GD₂ antibody (Ab) dinutuximab beta against GBM.

Methods

Expression levels of GD2 and complement regulatory proteins (CRP; CD46, CD55 and CD59) on well-known and newly established primary tumor originated GBM cell lines were analyzed by flow cytometry. Ab-dependent cellular (ADCC) and complement-dependent cytotoxicity (CDC) mediated by dinutuximab beta against GBM cells were determined by a non-radioactive calcein-AM-based assay.

Results

Analysis of primary GBM cells revealed a heterogeneous GD2 expression that varied between the cell lines analyzed with higher expression levels in the tumor surface compared to the core originated cells. Both GD2-positive and -negative tumor cells were detected in every cell line analyzed. In contrast to CDC, ADCC mediated by dinutuximab beta was observed against the majority of GBM cells. Importantly, CDC-resistant cells showed high expression of the CRP CD46, CD55 and CD59.

Conclusion

Our present data show anti-tumor effects mediated by dinutuximab beta against GBM cells providing a rationale for a GD2-directed immunotherapy against GBM. Due to high CRP expression, a combining of GD2-targeting with CRP blockade might be a further treatment option for GBM.

中文翻译：

---

地丁单抗β靶向GD2是一种有前景的针对恶性神经胶质瘤的免疫治疗方法。

目的

双唾液酸神经节苷脂GD ₂由多形胶质母细胞瘤（GBM）细胞表达，代表抗GD2免疫治疗方法的有希望的靶标。本研究的目的是研究嵌合抗GD ₂抗体（Ab）dinutuximab beta对GBM的抗肿瘤功效。

方法

通过流式细胞术分析了GD2和补体调节蛋白（CRP； CD46，CD55和CD59）在众所周知的和新近建立的原发性肿瘤起源的GBM细胞系中的表达水平。通过基于非放射性钙黄绿素-AM的测定法确定了地丁单抗β介导的针对GBM细胞的Ab依赖性细胞（ADCC）和补体依赖性细胞毒性（CDC）。

结果

对原代GBM细胞的分析显示，与核心来源的细胞相比，在肿瘤细胞表面具有更高表达水平的细胞系之间，GD2表达有所不同。在每个分析的细胞系中均检测到GD2阳性和阴性的肿瘤细胞。与CDC相反，在大多数GBM细胞中观察到了由dinutuximab beta介导的ADCC。重要的是，抗CDC的细胞显示出CRP CD46，CD55和CD59的高表达。

结论

我们目前的数据显示，地丁单抗β介导的针对GBM细胞的抗肿瘤作用为GD2定向针对GBM的免疫疗法提供了理论依据。由于高CRP表达，靶向GD2和CRP阻断的结合可能是GBM的另一种治疗选择。