Targeting the right regulatory T-cell population for tumor immunotherapy

Regulatory T cells (T-regs) that suppress tumor-specific T cell-mediated immune responses are the subject of an intense wave of investigation. We recently reported that a subset of T-regs, namely effector/memory CD25(low) cells, are responsible for suppressing high avidity tumor-specific T cells in mouse mammary tumors. Here, we discuss additional findings that clarify this mechanism of T-reg-mediated immunosuppression.