Abstract
The concept of regulatory T cell (T(reg) ) therapy in transplantation is now a reality. Significant advances in science and technology have enabled us to isolate human T(regs) , expand them to clinically relevant numbers and infuse them into human transplant recipients. With several Phase I/II trials under way investigating T(reg) safety and efficacy it is now more crucial than ever to understand their complex biology. However, our journey is by no means complete; results from these trials will undoubtedly provoke both further knowledge and enquiry which, alongside evolving science, will continue to drive the optimization of T(reg) therapy in the pursuit of transplantation tolerance. In this review we will summarize current knowledge of T(reg) biology, explore novel technologies in the setting of T(reg) immunotherapy and address key prerequisites surrounding the clinical application of T(regs) in transplantation.