Blocking tumor immunosuppression

Immunology Tumor-derived regulatory T cells (Tregs) suppress the antitumor effects of CD8+ T cells. Budhu et al. investigated the underlying mechanisms with an in vitro system that recreated some of the key features of the in vivo tumor microenvironment. Tregs inhibited the antitumor activity of CD8+ T cells toward cocultured melanoma cells from mouse tumors through the cytokine TGF-β (transforming growth factor-β), which increased the levels of an immune checkpoint protein on CD8+ T cells. A TGF-β-blocking antibody prevented immunosuppression, suggesting a therapeutic strategy to inhibit Treg activity in tumors. Sci. Signal. 10 , eaak9702 (2017).