Graft loss from chronic rejection affects all solid organs to varying degrees and has become the major obstacle to the long-term success of heart transplantation. The applicants have established a clinically relevant large animal model of chronic heart transplant rejection, manifested by the development of cardiac allograft vasculopathy (CAV), using MHC inbred miniature swine. During the previous grant period, they characterized the effects of class I MHC incompatibilities on the pathogenesis of CAV. The current proposal is designed to extend these studies by elucidating cellular and molecular mechanisms of chronic rejection in class I disparate hearts. Their hypothesis, based on emerging rodent studies, is that CAV is mediated by an immune process initiated by CD4+ T cells, which recognize MHC antigens via the indirect pathway of allorecognition and require a co-stimulatory signal for full activation. The corollary is that protocols to inhibit CD4+ T cell activation and induce tolerance to the indirect pathway will most effectively prevent, interrupt, and/or reverse vasculopathy. They plan to use the MHC class I disparate model to: 1) investigate the role and mechanisms of indirect allorecognition and the development of CAV, 2) define the role of T cell co-stimulatory pathways in the pathogenesis of CAV, and 3) determine whether the induction of peripheral (by co-stimulatory blockade) or central tolerance (using mixed chimerism and thymoheart allografts) can prevent CAV. These studies should lead to a better understanding of the cellular and molecular mechanisms of chronic rejection in a clinically relevant experimental model and may lead to the development of new strategies to prevent or treat this process.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
3R01HL054211-05S1
Application #
6313440
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Project Start
1996-08-01
Project End
2002-07-31
Budget Start
2000-08-01
Budget End
2001-07-31
Support Year
5
Fiscal Year
2000
Total Cost
$85,500
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02199
Meltzer, A J; Veillette, G R; Aoyama, A et al. (2012) Donor brain death inhibits tolerance induction in miniature swine recipients of fully MHC-disparate pulmonary allografts. Am J Transplant 12:1290-5
Veillette, Gregory R; Sahara, Hisashi; Meltzer, Andrew J et al. (2011) Autoimmune sensitization to cardiac myosin leads to acute rejection of cardiac allografts in miniature swine. Transplantation 91:1187-91
Hirohashi, T; Uehara, S; Chase, C M et al. (2010) Complement independent antibody-mediated endarteritis and transplant arteriopathy in mice. Am J Transplant 10:510-7
Weiss, M J; Guenther, D A; Mezrich, J D et al. (2009) The indirect alloresponse impairs the induction but not maintenance of tolerance to MHC class I-disparate allografts. Am J Transplant 9:105-13
Ng, Choo Y; Madsen, Joren C; Rosengard, Bruce R et al. (2009) Immunosuppression for lung transplantation. Front Biosci (Landmark Ed) 14:1627-41
Weiss, Matthew J; Madsen, Joren C; Rosengard, Bruce R et al. (2008) Mechanisms of chronic rejection in cardiothoracic transplantation. Front Biosci 13:2980-8
Hoerbelt, Ruediger; Benjamin, Christopher L; Shoji, Tsuyoshi et al. (2008) The effects of tolerance on allograft damage caused by the innate immune system. Transplantation 85:314-22
Houser, Stuart; Muniappan, Ashok; Allan, James et al. (2007) Cardiac allograft vasculopathy: real or a normal morphologic variant? J Heart Lung Transplant 26:167-73
Hoerbelt, R; Benjamin, L C; Shoji, T et al. (2006) Effects of tolerance induction on the actions of interferon-gamma on porcine cardiac allografts. Transplant Proc 38:3196-8
Weiss, Matthew J; Ng, Choo Y; Madsen, Joren C (2006) Tolerance, xenotransplantation: future therapies. Surg Clin North Am 86:1277-96, viii

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