Regulation of the immune response to both self-antigens and foreign pathogens is integral to host survival. The natural regulatory pathways involved may also afford the opportunity to intercede in undesirable immune responses such as those occurring to allogeneic transplants. The attractiveness of this approach is evident in the enthusiasm for applying regulatory T cells (Tregs) to promote transplant survival in patients. Recent evidence suggests that parallel regulatory pathways may exist in the humoral arm of the immune response though the exact cells involved and the mechanisms of regulation are yet to be fully characterized. Despite the convincing evidence for regulatory B cells (Bregs) in non-transplant settings (autoimmunity, infectious disease, and bone marrow transplant/GVHD), a clear role for B cells or Bregs in the maintenance of induced transplant tolerance has not yet been well-established. During the last funding period we made the unexpected observation that a well-studied model of antibody induced transplantation tolerance depends on the presence of B lymphocytes and that graft prolongation in the model was transferrable to secondary hosts by TIM-1+ B cells, demonstrating Breg activity. In the proposed studies, we will characterize the contribution of Bregs to transplantation tolerance using models developed in the previous funding period.
In Aim I, we focus on the mechanisms by which Bregs suppress the response of na?ve Teff and examine Breg antigen specificity, characterize Breg induced changes in the character of the immune response and define the role of immunomodulatory cytokines (IL-10 and TGF-?).
In Aim II, we will take advantage of our finding that anti-CD45RB-induced tolerance is dependent on both Tregs and B cells to explore the possibility that Treg development is fostered by Bregs or that Tregs and Bregs collaborate to promote graft acceptance. Finally, Aim III examines the contribution of the costimulatory molecule TIM-1 to tolerance induced by anti-CD45RB and will rely on a new TIM1-/- line generated by our collaborator, Dr Terry Strom. Collectively, these studies will further our understanding of the unique contribution of regulatory B cells to transplantation tolerance.

Public Health Relevance

T cell mediated regulation (by Tregs) of tolerance and rejection is now well-established. In the current work we explore the potential for parallel regulatory pathways in the humoral arm of the adaptive immune response by Bregs. Preliminary data suggest that B cells are critical to tolerance induced by a number of tolerogenic antibody regimens. We will study the mechanisms by which Bregs mediated tolerance in these models and how they collaborate with Tregs.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI057851-09
Application #
8608994
Study Section
Transplantation, Tolerance, and Tumor Immunology (TTT)
Program Officer
Rice, Jeffrey S
Project Start
2003-12-01
Project End
2017-02-28
Budget Start
2014-03-01
Budget End
2015-02-28
Support Year
9
Fiscal Year
2014
Total Cost
$430,936
Indirect Cost
$132,709
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02199
Wang, Ping; Schuetz, Christian; Vallabhajosyula, Prashanth et al. (2015) Monitoring of Allogeneic Islet Grafts in Nonhuman Primates Using MRI. Transplantation 99:1574-81
Kim, James I; Rothstein, David M; Markmann, James F (2015) Role of B cells in tolerance induction. Curr Opin Organ Transplant 20:369-75
Vergani, Andrea; Gatti, Francesca; Lee, Kang M et al. (2015) TIM4 Regulates the Anti-Islet Th2 Alloimmune Response. Cell Transplant 24:1599-614
Zhao, Gaoping; Moore, Daniel J; Kim, James I et al. (2014) An immunosufficient murine model for the study of human islets. Xenotransplantation 21:567-73
Lee, Kang Mi; Stott, Ryan T; Zhao, Gaoping et al. (2014) TGF-β-producing regulatory B cells induce regulatory T cells and promote transplantation tolerance. Eur J Immunol 44:1728-36
Corritore, Elisa; Dugnani, Erica; Pasquale, Valentina et al. (2014) β-Cell differentiation of human pancreatic duct-derived cells after in vitro expansion. Cell Reprogram 16:456-66
Lee, Kang Mi; Yeh, Heidi; Zhao, Gaoping et al. (2014) B-cell depletion improves islet allograft survival with anti-CD45RB. Cell Transplant 23:51-8
Martins, Paulo Ney Aguiar; Tullius, Stefan G; Markmann, James F (2014) Immunosenescence and immune response in organ transplantation. Int Rev Immunol 33:162-73
Yeh, Heidi; Moore, Daniel J; Markmann, James F et al. (2013) Mechanisms of regulatory T cell counter-regulation by innate immunity. Transplant Rev (Orlando) 27:61-4
Lee, Jonghyeob; Sugiyama, Takuya; Liu, Yinghua et al. (2013) Expansion and conversion of human pancreatic ductal cells into insulin-secreting endocrine cells. Elife 2:e00940

Showing the most recent 10 out of 20 publications