Organ-specific Differences in a Thymoglobulin and Belatacept-based Protocol for Tolerance Induction in Non-human Primates

Abstract

In non-human primate lung transplantation, allograft acceptance has been achieved using a delayed mixed-chimerism approach consisting of 4 months of triple-drug immunosuppression (FK, MMF, steroids) followed by donor bone marrow transplantation (DBMT) along with equine-ATG, anti-IL6R mAb, anti-CD154 mAb and anti-CD8 mAb. With this protocol, 3 out of 4 monkeys accepted their grafts long-term (>299, >813, >464 days). However, anti-CD154mAb and anti-CD8 mAb are not clinically available. In kidney transplantation, persistent allograft acceptance in Cynomolgus macaques was achieved using an alternative immunosuppression protocol relying on the clinically available reagents, rabbit-ATG and belatacept. Here, we have tested the same protocol in Cynomolgus macaques transplanted with fully allogeneic lung grafts.