Targeting regulatory T cells in glioblastoma: from mechanistic insights to novel immunotherapeutic strategies

Glioblastoma (GBM), the most common and aggressive primary brain tumor in adults, remains a formidable therapeutic challenge. Within the immunosuppressive tumor microenvironment, regulatory T cells (Tregs) have attracted increasing attention for their pivotal role in facilitating tumor immune evasion and sustaining immunosuppression. Through diverse mechanisms, Tregs potently inhibit anti-tumor immunity, thereby driving tumor progression and contributing to therapeutic resistance, which collectively correlates with poor clinical outcomes. This review systematically outlines the biological features and regulatory networks of Tregs in GBM, with particular emphasis on emerging strategies designed to target these cells. We discuss approaches such as Treg depletion, interference with their recruitment, functional reprogramming, and combination immunotherapies. Furthermore, we critically assess the translational progress and clinical limitations of these approaches, including challenges related to target specificity, immune adaptation, and treatment-related toxicities. By synthesizing mechanistic insights with therapeutic prospects, this review aims to inform future directions in precision immunotherapy and inspire multidisciplinary efforts toward effective Treg-targeting regimens for GBM.