Early-career research(J-PEAKS)

Chimeric antigen receptor-transfected T cells (CAR-T cells), which possess both the protein recognition site of an antibody and the T cell receptor signaling site, are a revolutionary cancer immuno-cell therapy that enables T cells that would normally not recognize cancer cells to recognize cancer cells and exert cytotoxic activity. For example, in B-cell acute lymphocytic leukemia that expresses CD19, the advent of CD19-targeted CAR-T cell therapy has made it possible to save the lives of patients with intractable disease who could not be cured by chemotherapy or hematopoietic stem cell transplantation alone. However, CAR-T cell therapy for acute myeloid leukemia (AML) and solid tumors, other than B-cell hematopoietic tumors such as CD19 and BMCA, is still under development.

Chiba University is conducting clinical development of immunotherapy targeting NKT cells, a type of immune cell of the innate immune system that recognizes and injures various types of cancer cells regardless of cancer type. At the same time, they produce a large amount of cytokines and play a role in activating other immune cells, such as NK cells, dendritic cells, and T cells. We have previously shown that CAR-NKT cells, which express CAR on NKT cells, exhibit different therapeutic effects from CAR-T cells. In this study, we will develop CAR-NKT cell therapy for AML, which is difficult to be treated with conventional CAR-T cell therapy.

Unlike conventional T cells, NKT cells are difficult to culture in large quantities, so we have developed iPS cell-derived NKT cells in collaboration with RIKEN. iPS cell-derived NKT cell therapy has now completed investigator-initiated clinical trials and is being manufactured and developed by a company. We are therefore also developing therapies using iPS cell-derived NKT cells in this study.

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