Moving to tolerance: clinical application of T regulatory cells

Abstract

Decreasing the incidence of chronic rejection and reducing the need for life-long immunosuppression remain important goals in clinical transplantation. In this article, we will review how regulatory T cells (Treg) came to be recognized as an attractive way to prevent or treat allograft rejection, the ways in which Treg can be manipulated or expanded in vivo, and the potential of in vitro expanded/generated Treg for cellular therapy. We will describe the first regulatory T cell therapies that have been or are in the process of being conducted in the clinic as well as the safety concerns of such therapies and how outcomes may be measured.

Figure 1. Approaches and outstanding questions for Treg cell therapy in organ transplantation

Animal models have illustrated the potential of many different methods to enhance the numbers and/or function of Tregs in the context of solid organ transplantation. Although there are still many outstanding questions that must be answered to optimise this approach, the results from ongoing and planned clinical trials will be critical to illustrate whether this therapy can reduce the dependence on pharmacological immunosuppression.