A Review of Current Strategies to Achieve Tolerance in Animal Models

Abstract

The current objective of transplantation is to prolong allograft survival indefinitely without the complications associated with chronic immunosuppression (infection, malignancy, adverse metabolic effects, drug toxicity) and without the development of chronic rejection. However, the ultimate goal of all transplant surgeons, the ``Holy Grail'' of transplantation, is to achieve indefinite clinical allograft acceptance without the need for long-term immunosuppression while the immune response to all other antigens remains intact --- donor-specific tolerance [1, 2]. Over the last 50 years, various strategies have been tried to induce transplantation tolerance. Many of these have been validated in rodent models but have shown less degrees of success after extension to large animals, nonhuman primates and humans.