Minireview: Regulatory T Cells and Ovarian Cancer.

In the last 15 years, it has become apparent that ovarian cancer is recognized by the immune system, taking into account that T cell infiltration can be associated with increased overall survival. Several studies indicate that a correct combination of cluster of differentiation 8 and cluster of differentiation 4 T cells is key to fight tumor progression and that the presence of regulatory T cells (Tregs) infiltrating ovarian solid tumors (or present in ascites) is deleterious. Several markers that characterize Tregs include glucocorticoid-induced tumor necrosis factor receptor, cytotoxic T lymphocyte antigen-4, and forkhead box protein 3 (Foxp3). Research has shown that Tregs can infiltrate cancerous tissue and contribute to tumor growth by secreting immunosuppressive cytokines such as transforming growth factor beta and interleukin (IL)-10. Importantly, these cells might hamper the efficacy of immunotherapeutic approaches, thus strategies involving depletion or regulation of this population have been proposed and tested in experimental models. In this Minireview, we will discuss the relevance of Tregs in ovarian cancer and the experimental approaches destined to impair their immunosuppressive effects.