Glioma is the most common primary brain cancer, and half of patients present a diagnosis of glioblastoma (GBM), its most aggressive and lethal form. Conventional therapies, including surgery, radiotherapy, and chemotherapy, have not resulted in major ameliorations in GBM survival outcome, which remains extremely poor. Recent immunotherapy improvements for other tumors, coupled with growing knowledge of the complex interactions between malignant glioma cells and the immune system, led to an exponential increase in glioma immunotherapy research. However, immunotherapeutic strategies in GBM have not yet reached their full potential, mainly due to the limited understanding of the strong immunosuppressive microenvironment (TME) characterizing this tumor. Glioma-associated macrophages and microglia (GAMs) are key drivers of the local immunosuppression promoting tumor progression and its resistance to immunomodulating therapeutic strategies. Together with other myeloid cells, such as dendritic cells and neutrophils, GAMs actively shape glioma TME, modulate anti-tumoral immune response and support angiogenesis, tumor cell invasion and proliferation. In this review, we discuss the role of myeloid cells in the complex TME of glioma and the available clinical data on therapeutic strategies focusing on approaches that affect myeloid cells activity in GBM.

中文翻译：

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胶质瘤中髓样细胞在免疫抑制微环境中的作用。

胶质瘤是最常见的原发性脑癌，一半的患者诊断出胶质母细胞瘤（GBM），它是最具攻击性和致死性的形式。包括外科手术，放射疗法和化学疗法在内的常规疗法并未对GBM生存结果产生重大改善，而GBM生存结果仍然极差。最近针对其他肿瘤的免疫疗法的改进，加上对恶性神经胶质瘤细胞与免疫系统之间复杂相互作用的日益了解，导致神经胶质瘤免疫疗法研究呈指数级增长。但是，GBM中的免疫治疗策略尚未发挥出全部潜力，这主要是由于对这种肿瘤特征性的强免疫抑制微环境（TME）的了解有限。胶质瘤相关的巨噬细胞和小胶质细胞（GAMs）是促进肿瘤进展及其对免疫调节治疗策略的抵抗力的局部免疫抑制的关键驱动力。GAM与其他髓样细胞（例如树突状细胞和嗜中性粒细胞）一起积极塑造神经胶质瘤TME，调节抗肿瘤免疫应答并支持血管生成，肿瘤细胞的侵袭和增殖。在这篇综述中，我们讨论了髓样细胞在神经胶质瘤的复杂TME中的作用，以及有关治疗策略的可用临床数据，重点是影响GBM中髓样细胞活性的方法。调节抗肿瘤免疫反应并支持血管生成，肿瘤细胞侵袭和增殖。在这篇综述中，我们讨论了髓样细胞在神经胶质瘤的复杂TME中的作用，以及有关治疗策略的可用临床数据，重点是影响GBM中髓样细胞活性的方法。调节抗肿瘤免疫反应并支持血管生成，肿瘤细胞侵袭和增殖。在这篇综述中，我们讨论了髓样细胞在神经胶质瘤的复杂TME中的作用，以及有关治疗策略的可用临床数据，重点是影响GBM中髓样细胞活性的方法。