Approach to new immune cell therapies in the age of regenerative medicine (LL3-5)

Abstract

In the field of organ transplantation, various efforts have been made to explore the potential for immunological tolerance to resolve issues which result from immunosuppression such as side effects or infection. We have reported the results of our long-term research about transplant tolerance, mainly induced by blocking of T-cell costimulatory signals. In 2005, we reported a protocol that makes possible long-term (>2 years) tolerance in monkey allogenic kidney transplantation (JCI 115:1896-902, 2005). Currently, we are performing clinical trials of the tolerance induction in living-donor kidney transplants as collaboration with Tokyo Women's Medical University and Juntendo University. We plan to apply same protocol to liver transplant cases in the near future in Hokkaido. With the recent establishment of pluripotent stem cells (ES or iPS cells), hopes for development of regenerative medicine are growing. Although it is expected that immunological rejection will not occur when using iPS cells, the need for immunosuppression will still continue to exist with a framework of stem cell banking. In the future, new kinds of research fused with the study of organ transplantation including immunological tolerance will be necessary to advance clinically-oriented regenerative medicine. For instance, one new strategy is to use pluripotent stem cells to manufacture cells to serve as the source of tolerance, and administer these cells to recipients along with ES/iPS cell-derived transplant tissues. This lecture will address mechanisms of transplant tolerance, expertise accumulated thus far through our clinical practice, as well as future possibilities for immune-regulation in the age of regenerative medicine.