Mass-Production of Cytotoxic T Lymphocytes Regenerated from Pluripotent Stem Cells-To Target Solid Tumors

Current adoptive T cell therapies conducted in an autologous setting are costly, time consuming, and depend on the quality of the patient's T cells. To address these issues, we developed a strategy in which T cells are regenerated from induced pluripotent stem cells (iPSCs) that were originally derived from T cells, and succeeded in regenerating cytotoxic T lymphocytes (CTLs) specific for the WT1 antigen, which exhibited therapeutic efficacy in a xenograft model of leukemia. We recently have extended our strategy to solid tumors. To make our method more generally applicable, we developed an allogeneic approach by transducing HLA-haplotype homozygous iPSCs with WT1-specific TCR a/8 genes that had been tested clinically. The regenerated CTLs antigen-specifically suppressed tumor growth in a patient-derived xenograft model of renal cell carcinoma, demonstrating the feasibility of our strategy against solid tumors.