Memory Antitumor T-Cells Resist Inhibition by Immune Suppressor Cells

Cancer immune therapy is difficult partly because several classes of suppressor cells, including regulatory T-cells and macrophage-derived suppressor cells, inhibit the antitumor T-cell response. We used treatment studies of implanted tumors in mice to demonstrate that the same inhibitory cells that abrogated an acute therapeutic T-cell response to established tumor did not inhibit the therapeutic response produced by memory T-cells. Generating antitumor memory T-cells may be a highly potent strategy against cancer with late developing metastases.