Regulatory T cells in ovarian cancer: Insights into cancer immunotherapy

Ovarian cancer (OC) is a formidable malignancy characterized by a notably diminished five-year survival rate. Current evidence demonstrates that OC orchestrates the establishment of an immunosuppressive tumor microenvironment (TME), thereby affording tumor cells a favorable milieu to evade immune surveillance and resist therapeutic interventions. Central to this immunosuppressive landscape are regulatory T cells (Tregs), which infiltrate both tumor sites and circulation. Within the TME, OC cells interact with these Tregs and other immunosuppressive networks to promote tumorigenesis, progression, and metastasis. Recent investigations have predominantly concentrated on elucidating the activation mechanisms and diverse functional states of Tregs across distinct human pathologies. Nevertheless, further study is needed to revolve around the substantial contributions of tumor-infiltrating Tregs in the context of OC. In this review, we provide an overview of present advances in Tregs' heterogeneity and their multifaceted functions within the TME, encompassing immunologic tolerance, immune evasion, metabolic reprogramming, and microenvironmental remodeling. By integrating TME and therapy perspectives on Tregs in OC, this review bridges existing gaps in the literature and aims to offer emerging insights for precise immunotherapeutic strategies specifically for OC.