Hallmarks of the Tumour Microenvironment of Gliomas and Its Interaction with Emerging Immunotherapy Modalities

Gliomas are aggressive, primary central nervous system tumours arising from glial cells. Glioblastomas are the most malignant. They are known for their poor prognosis or median overall survival. The current standard of care is overwhelmed by the heterogeneous, immunosuppressive tumour microenvironment promoting immune evasion and tumour proliferation. The advent of immunotherapy with its various modalities-immune checkpoint inhibitors, cancer vaccines, oncolytic viruses and chimeric antigen receptor T cells and NK cells-has shown promise. Clinical trials incorporating combination immunotherapies have overcome the microenvironment resistance and yielded promising survival and prognostic benefits. Rolling these new therapies out in the real-world scenario in a low-cost, high-throughput manner is the unmet need of the hour. These will have practice-changing implications to the glioma treatment landscape. Here, we review the immunobiological hallmarks of the TME of gliomas, how the TME evades immunotherapies and the work that is being conducted to overcome this interplay.

Automated summary

Gliomas are aggressive tumors originating from glial cells in the central nervous system. Glioblastomas, the most malignant form, have a poor prognosis. The tumor microenvironment (TME) in gliomas is heterogeneous and immunosuppressive, promoting immune evasion and tumor growth. Immunotherapies, such as immune checkpoint inhibitors and chimeric antigen receptor T cells, have shown promise in overcoming TME resistance and improving survival. However, there is a need to implement these therapies in a cost-effective and efficient manner to benefit glioma patients.