Chimerism and xenotransplantation - New concepts

The migration and localization of antigens govern immunologic responsivenes s or unresponsiveness against infections, tumors, self, xenografts, and all ografts. Evidence summarized in this article supports that donor leukocyte chimerism is a prerequisite for, but is not synonymous with and is not a co nsequence of, the evolution of organ allograft acceptance. Only with an und erstanding of this concept will it be possible to develop innovative strate gies for tolerance induction to allografts and strategies, such as those de scribed here, for successful xenotransplantation.