Administration of tolerogenic dendritic cells induced by interleukin-10 prolongs rat splenic allograft survival.

The risk and intensity in splenic graft rejection are greater than in other types of transplants, because the spleen is the largest peripheral lymphoid organ and the immunosuppressive drugs administered can cause splenic dysfunction. In this study, we demonstrate that intravenous injection of interleukin-10-treated donor-type dendritic cells into recipient rats prolongs the survival of splenic allografts. Although the mechanisms are not clear, the induction of tolerance to grafted spleens seems to rely mainly on blockage of expression of the costimulatory molecule CD86, by interleukin-10, leading to enhanced apoptosis of allospecific T cells by immature and tolerogenic dendritic cells. Administration of tolerogenic cells induced by interleukin-10 may thus represent a useful approach for protection of splenic allografts. Further study is required to investigate the operative pathways and to optimize the strategy targeting dendritic cells to induce tolerance in splenic allografts.