Abstract: The present invention features a method of inducing donor-specific tolerance in a host. Tolerogenic treatments of the present invention may be administered to a host prior to transplantation of donor-derived materials. The tolerogenic treatment involves (1) administering an immunosuppressive agent to a host mammal in a non-myeloablative regimen sufficient to decrease, but not necessarily to eliminate, the host mammal's functional T lymphocyte population; (2) infusing donor antigens from a non-syngeneic donor into the host mammal; (3) eliminating those host T lymphocytes responding to the infused donor antigens using a non-myeloablative dose of lymphocytotoxic or tolerizing agent; and (4) administering donor hematopoietic cells to the host mammal. Donor lymphoid cells used for cell therapy of a host mammal can be depleted of host specific immunological reactivity by methods essentially similar to those use for tolerizing a host mammal prior to transplantation.

Abstract: In general, the invention features, a method of inducing tolerance in a recipient mammal, e.g., a human, of a first species to a tissue obtained from a mammal, e.g., a swine, e.g., a miniature swine, of a second species, which tissue expresses an MHC antigen, including inserting DNA encoding an MHC antigen of the second species into a bone marrow hematopoietic stem cell from the recipient mammal, and allowing the MHC antigen encoding DNA to be expressed in the recipient.