Role of T and dendritic cells in mouse islet allografts treated with anti-CD45RB monoclonal antibodies.

Currently lifelong immunosuppression is required for organ transplant recipients. Anti-CD45RB monoclonal antibody (mAb) prolongs graft survival by mechanisms that are not yet clear. Therefore, we investigated the role of T and dendritic cells (DC) in islet allografts treated with anti-CD45RB mAb after transplantation of 200 allogeneic islets (BALB/c mouse) under the kidney capsules of diabetic C57BL/6 mice treated with intraperitoneal injections of 100 μg of anti-CD45RB mAb on days 0, 1, 3, 5, and 7. We observed a tilt of the ratios of Th1/Th2 and Tc1/Tc2 to Th2 and Tc2. The numbers of naïve and memory T cells were down-regulated in peripheral blood after transplantation. In addition, the maturation, endocytosis, and interleukin-12 secreted by DC derived from bone marrow cells was suppressed in recipient mice. Therefore, anti-CD45RB mAb alleviated, rejection by suppressive effects on T-lymphocyte subsets and DC.