Tolerance to vascularized organ allografts in large-animal models.

Although studies of tolerance induction in large animals remain limited compared with murine studies, a number of encouraging observations have been recently reported - especially in nonhuman primate models. The development of antibodies or proteins binding to costimulatory molecules and of an immunotoxin that is active on T cells have been particularly important advances leading to expanded opportunities for extending strategies for tolerance induction to large animals.