In Vitro Generation of Stem Cell Memory-Like T Cells from Activated T Cells

Adoptive T-cell therapy is an attractive strategy for cancer immunotherapy. The transfer of in vitro expanded tumor-associated antigen (TAA)-specific T cells from patients may effectively fight against the original tumor cells. The chimeric antigen receptor-engineered T (CAR-T) cells are also shown to be a promising therapy for hematologic malignancies. However, one of the limitations of these T-cell-based therapies is a rapid acquisition of tolerant (anergy, deletion, dysfunctional and/or exhausted) phenotypes of T cells during activation in vitro and/or after transfer in vivo. We and others found that stem cell memory T (T_SCM) cells are strongly resistant against such tolerance, showing strong expansion and persistence in vivo, and provide long-lasting antitumor effects. Here we describe a protocol for the generation of phenotypically T_SCM-like cells (iT_SCM cells), which can be induced by simple co-culture of activated T cells with OP9 stroma cells expressing a Notch ligand. We also showed the methods of cancer immunotherapy by using NSG mice.