title: Achieving tolerance in pig-to-primate xenotransplantation: reality or fantasy.
abstract: Because the immunologic differences between species are far greater than those within species, it is likely that the amount of immunosuppression that would be required for successful xenografting would be so much greater than that now used for allografting, that the side-effects and complications would be unacceptable. Tolerance approaches to xenotransplantation would overcome this concern. Studies in humanized mouse models have demonstrated that human T cells can be tolerized to porcine xenografts, providing important proofs of principle of the potential feasibility of pig-to-primate xenograft tolerance. The results available from studies of pig-to-primate xenotransplantation to date have demonstrated that while chronic immunosuppressive drugs have not completely avoided either T cell responses or humoral rejection, approaches directed toward tolerance induction have been encouraging with regard to avoiding immunization at both of these levels.
authors.affiliation: Transplantation Biology Research Center, Massachusetts General Hospital and Harvard Medical School Boston, Massachusetts, USA. david.sachs@tbrc.mgh.harvard.edu
authors.forename: David H
authors.initials: DH
authors.lastname: Sachs
authors.forename: Megan
authors.initials: M
authors.lastname: Sykes
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamada
mesh_terms: D000818:Animals; D046528:Chimerism; D005240:Feasibility Studies; D006084:Graft Rejection / Q000276:immunology* / Q000517:prevention & control; D006801:Humans; D056724:Immunity, Humoral; D051379:Mice; D016377:Organ Transplantation; D011323:Primates; D013552:Swine; D013601:T-Lymphocytes / Q000276:immunology*; D023001:Transplantation Tolerance; D014183:Transplantation, Heterologous