Tolerogenic dendritic cell therapy in organ transplantation

Although the occurrence of acute rejection was significantly reduced and the allograft survival at 1 year was massively improved by the development of pharmacological immunosuppressive drugs, little progress has been made regarding long-term graft survival. Cell therapy appears to be an innovative and promising strategy to minimize the use of immunosuppression in transplantation and consequently increases long-term graft survival. The strength of cell therapy is that it will induce graft-specific tolerance and not a general immunosuppression of the patients. Several candidates, such as tolerogenic dendritic cells, have been gaining interest as an efficient means of promoting antigen-specific tolerance over recent years. Studies performed in rodent models have demonstrated the feasibility and efficacy of tolerogenic dendritic cells for the induction of tolerance in transplantation. In parallel, protocols to generate human tolerogenic dendritic cells in vitro have been defined, and some phase I clinical trials in autoimmune diseases have been recently performed to evaluate the safety of tolerogenic dendritic cell therapy. In this review, we will focus on the potential therapeutic interest of these cells in transplantation as well as their generation and characterization in humans. Finally, we will describe our current clinical trial using autologous tolerogenic dendritic cells in transplantation.