Strategies for immune regulation in iPS cell-based cardiac regenerative medicine.

Cardiac regenerative therapy is expected to be a promising therapeutic option for the treatment of severe cardiovascular diseases. Artificial tissues or organoids made from cardiovascular cell lineages differentiated from human induced pluripotent stem cells (iPSCs) are expected to regenerate the damaged heart. Even though immune rejection rarely occurs when iPSC-derived graft and the recipient have the same HLA type, in some cases, such as tissue transplantation onto hearts, the HLA matching would not be sufficient to fully control immune rejection. The present review introduces recent immunomodulatory strategies in iPSC-based transplantation therapies other than MHC matching including the induction of immune tolerance through iPSC-derived antigen-presenting cells, simultaneous transplantation of syngeneic mesenchymal stem cells, and using the universal donor cells such as gene editing-based HLA modulation in iPSCs to regulate T cell compatibility. In addition, we present future perspectives for proper adjustment of immunosuppression therapy after iPSC-derived tissue/organoid-based cardiac regenerative therapies by identifying biomarkers monitoring immune rejection.