Although non-specific immunosuppression is clinically successful, it is associated with serious complications. Thus, tolerance remains an important goal. Tolerance frequently involves multiple sequential mechanisms. Polyclonal antilymphocyte serum (ALS) and donor bone marrow (BM) has induced tolerance in several species and is currently undergoing clinical trial. Rapamycin given after ALS and BM dramatically increases tolerance. This observation provides an opportunity to study the mechanisms involved in tolerance induction and maintenance in a clinically relevant model. Animals (mice) will be rendered tolerant by ALS, BM and Rapamycin and studied sequentially in the central and peripheral lymphoid tissues for chimerism (FACS analysis), the frequency of recipient tolerogen reactive (pCTLs) cells (limiting dilution analysis), the percentage of recipient cells with TcR specific for tolerogen (Mls-1 differences) and suppressor cells (standard transfer assays). Suppressor cell source (host or donor), cell type and phenotype will be identified by depletion steps using specific monoclonal antibodies (mAb) prior to transfer. Differential activation of Th1 and Th2 helper cells will be determined by sequential analysis of specific cytokine secretion (IL-2, INF-g, IL-4, IL-10) in MLC supernatants (ELISA assays) and of specific cytokine mRNA of lymphoid tissues using reverse transcriptase polymerase chain reaction. These studies should demonstrate what mechanisms function at various stages of tolerance in this model. In adult thymectomized recipients given ALS and BM, transplantation of donor thymus (ThyTx) increases tolerance. This observation is unique in that adult thymus is used in association with relatively minimal (ALS) immunosuppression. Experiments will study the type of thymus graft (normal, irradiated, cultured, thymocyte suspension) and the optimal conditions required for tolerance induction with ALS and BM. Sequential analysis of the various mechanisms of tolerance will be performed to define if and how the mechanisms of tolerance are altered in the ThyTx recipients. Additional experiments will attempt to increase tolerance after ALS, BM and Rapamycin with further manipulations of the recipient or donor thymus. These studies include attempts to augment tolerance after ALS, BM and Rapamycin by intrathymic injection of additional donor antigen , by donor ThyTx, and by reinforcing the tolerance with additional sequential injections of BM with or without additional immunosuppression. These experiments are designed to study the mechanism(s) involved in induction and maintenance of tolerance. Knowledge of the sequential mechanisms involved should lead to strategies to augment tolerance with strong potential for clinical application.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Kehn, Patricia J
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Beth Israel Deaconess Medical Center
United States
Zip Code
Wan, Xiaoxiao; Zinselmeyer, Bernd H; Zakharov, Pavel N et al. (2018) Pancreatic islets communicate with lymphoid tissues via exocytosis of insulin peptides. Nature 560:107-111
Ferris, Stephen T; Zakharov, Pavel N; Wan, Xiaoxiao et al. (2017) The islet-resident macrophage is in an inflammatory state and senses microbial products in blood. J Exp Med 214:2369-2385
Umemura, A; Monaco, A P; Maki, T (2001) Essential role of MHC class II antigens in tolerance induction in allogeneic radiation chimera. Transplant Proc 33:112
Monaco, A P; Maki, T; Hale, D et al. (2001) The enigma of tolerance and chimerism: variable role of T cells and chimerism in induction of tolerance with bone marrow. Transplant Proc 33:3837-9
Umemura, A; Morita, H; Li, X C et al. (2001) Dissociation of hemopoietic chimerism and allograft tolerance after allogeneic bone marrow transplantation. J Immunol 167:3043-8
Umemura, A; Monaco, A P; Maki, T (2000) Donor MHC class II antigen is essential for induction of transplantation tolerance by bone marrow cells. J Immunol 164:4452-7
Hale, D A; Gottschalk, R; Umemura, A et al. (2000) Establishment of stable multilineage hematopoietic chimerism and donor-specific tolerance without irradiation. Transplantation 69:1242-51
Umemura, A; Monaco, A P; Maki, T (2000) Donor T cells are not required for induction of allograft tolerance in mice treated with antilymphocyte serum, rapamycin, and donor bone marrow cells. Transplantation 70:1005-9
Hale, D A; Gottschalk, R; Maki, T et al. (1998) Determination of an improved sirolimus (rapamycin)-based regimen for induction of allograft tolerance in mice treated with antilymphocyte serum and donor-specific bone marrow. Transplantation 65:473-9
Hale, D A; Gottschalk, R; Fukuzaki, T et al. (1997) Superiority of sirolimus (rapamycin) over cyclosporine in augmenting allograft and xenograft survival in mice treated with antilymphocyte serum and donor-specific bone marrow. Transplantation 63:359-64

Showing the most recent 10 out of 24 publications