Consistent induction of donor-specific unresponsiveness in the absence of continuous
immunosuppressive therapy and toxic effects remains a difficult task in clinical organ
transplantation. Transplant immunologists have developed numerous experimental
treatments that target antigen-presentation (signal 1), costimulation (signal 2), and cytokine
production (signal 3) to establish transplantation tolerance. While promising results have
been obtained using therapeutic approaches that predominantly target the adaptive immune …