AUTHOR=Ruiz Paulina , Maldonado Paula , Hidalgo Yessia , Sauma Daniela , Rosemblatt Mario , Bono Maria Rosa 

TITLE=Alloreactive Regulatory T Cells Allow the Generation of Mixed Chimerism and Transplant Tolerance

JOURNAL=Frontiers in Immunology

VOLUME=Volume 6 - 2015

YEAR=2015

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2015.00596

DOI=10.3389/fimmu.2015.00596

ISSN=1664-3224

ABSTRACT=The induction of donor-specific transplant tolerance is one of the main goals of modern immunology. Establishment of a mixed chimerism state in the transplant recipient has proven to be a suitable strategy for the induction of long-term allograft tolerance; however, current experimental recipient preconditioning protocols have many side effects, and are not feasible for use in future therapies. In order to improve the current mixed chimerism induction protocols, we developed a non-myeloablative bone-marrow transplant protocol using retinoic acid induced alloantigen-specific Tregs, clinically available immunosuppressive drugs and lower doses of irradiation. We demonstrate that retinoic acid induced alloantigen-specific Tregs in addition to a non-myeloablative bone-marrow transplant protocol generates stable mixed chimerism and induce tolerance to allogeneic secondary skin allografts in mice. Therefore, the establishment of mixed chimerism through the use of donor-specific Tregs rather than non-specific immunosuppression could have a potential use in organ transplantation.