The Induction of Mixed Chimerism Using ES Cell-Derived Hematopoietic Stem Cells

The use of haematopoietic stem cell (HSC) transplantation for the establishment of mixed chimerism generally leads to durable immune tolerance to allografts in animal models of transplantation. The development of reduced intensity regimens for achieving allogeneic haematopoietic engraftment across major histocompatibility complex (MHC) barriers and its recent application in clinical trials of kidney transplantation is encouraging. Embryonic stem cell-derived HSCs have lower immunogenicity and could, therefore, potentially be safer, inducing mixed chimerism and tolerance with minimal host pre-treatment and risk of graft versus host disease, despite crossing MHC barriers.