The Immunosuppressive Microenvironment of Glioblastoma: Mechanisms, Clinical Challenges, and Future Directions

Glioblastoma (GBM) poses a significant therapeutic challenge due to its highly immunosuppressive tumor microenvironment (TME). Current treatments, including surgery, radiotherapy, and chemotherapy, offer limited survival benefits, as the TME fosters immunological escape and tumor growth. This review analyzes the clinical limitations of current therapies, the complicated molecular mechanisms pathways driving immunosuppression in the GBM TME, and promising future solutions. We address the role of tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and the blood-brain barrier (BBB) in reinforcing immune evasion. Potential therapeutic approaches include targeting these immunosuppressive mechanisms by metabolic reprogramming, epigenetic modulation, and novel multi-modal therapies that might change treatment outcomes for GBM patients.