Stem-like CD8 T cells mediate response of adoptive cell immunotherapy against human cancer

Stem-like T cells mediate response Adoptive cell transfer (ACT) is a type of immunotherapy that uses a patient’s own T lymphocytes to recognize and attack cancer. ACT has been effective in treating certain patients with metastatic melanoma and is being applied to treat some epithelial cancers. Krishna et al. investigated why some cancer patients respond to ACT, whereas others do not. They identified a population of CD8 + T cells that had stem-like surface markers that were associated with effective tumor cell killing and favorable response of melanoma patients to ACT. Only a small subset of T cells specific against tumor mutations were found in this stem-like state, whereas most mutation-reactive T cells were terminally differentiated. These findings could be of value in improving cancer immunotherapy outcomes. Science , this issue p. 1328