In a new study appearing in the June 1 print issue of The Journal of Clinical Investigation, Nicholas Restifo and colleagues identified which cells are optimal for treating large, vascularized, established tumors. The authors use a mouse model that mimics the human clinical situation. They find that phenotypic and functional qualities of T cells are associated with the ability of ACT to cause regression of large, established melanomas. Seemingly paradoxical, naïve and early effector T cells are more effective for tumor treatment than more differentiated T cells.
In an accompanying commentary, Daniel Speiser and Pedro Romero write, "optimal therapeutic efficacy may depend on different T cell selection and preparation strategies" and these findings indicate that a pragmatic strategy for ACT is to keep the in vitro T cell expansion phase as short as possible to keep them naïve. These findings are important for development of improved adoptive immunotherapy approaches for treating tumors and established infectious diseases.
TITLE: Acquisition of full effector function in vitro paradoxically impairs the in vivo anti-tumor efficacy of adoptively transferred CD8+ T cells
TITLE: Towards improved immunocompetence of adoptively transferred CD8+ T cells