We seek to develop a clinically applicable strategy to induce """"""""true"""""""" transplantation tolerance treated with allochimeric Class I MHC molecules. Our novel findings in a rat cardiac allograft model provide the foundation of this proposal. We hypothesize: (i) allochimeric-induced tolerance is applicable to genetically diverse allograft recipients; (ii) allochimeric molecules modulate the immune response by indirect presentation; (iii) aIlochimeric molecules generate unique regulatory T cells with distinctive functional and TcR allospecificities. We propose: 1. To Define the Requirements of Different AIIochimeric Molecules to Induce Tolerance. Multiple allochimeric molecules, in different strain combinations, will be constructed to define critical immunogenic epitopes in the polymorphic regions of class I MHC. AIIochimeric molecules that display donor-dominant epitopes on recipient class I antigens will be tested for their ability to induce """"""""true"""""""" chronic rejection-free tolerance. 2. To Analyze AIIoimmune Modulation by Indirect Presentation of Allochimeric [alpha1h I/u]-RT1.Aa Class I MHC Molecules. Fine mapping of immunogenic/cryptic self-epitopes that are critical for allograft tolerance will be performed. Indirect allochimeric deviation of T cell responses will be addressed by employing host or donor-type dendritic cells that have been pulsed in vitro with donor wild-type or alpha1h 1/u]-RT1.Aa molecules. AIIochimeric protein labeling and detection will localize the site and cell-type involved in allochimeric processing and presentation. Requirement of 'immature vs mature' hepatic DC for allochimeric tolerance induction will be investigated in vivo by functional stimulation of DC maturity and allostimulatory capacity using FIt3L, a hematopoietic growth factor, to potentially abrogate indirectly induced tolerance following intra-portal allochimeric delivery. 3. To Characterize the Unique Population of Regulatory T Cells Induced by Indirect Allorecognition. We will perform in vivo and ex vivo phenotypic and functional characterization of regulatory T cells. Allochimeric generation of regulatory T cells, a possible key tolerogenic mechanism in this model, will be probed in vitro by studying immature hepatic dendritic cells that indirectly present allochimeric molecules to CD4+ T cells. Third, in vivo analysis of chronic rejection coupled with CDR3 spectrotyping, immunoscope and sequence analysis of allochimeric-induced clonally-restricted regulatory T cells will define unique T cell functional specificities and the influence of allochimeric sequence on the allospecific TcR repertoire.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI049945-04
Application #
6999763
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Macchiarini, Francesca
Project Start
2003-07-01
Project End
2007-12-31
Budget Start
2006-01-01
Budget End
2006-12-31
Support Year
4
Fiscal Year
2006
Total Cost
$260,604
Indirect Cost
Name
University of California Los Angeles
Department
Surgery
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Zhang, Li; You, Junping; Sidhu, Jitinderpal et al. (2013) Abrogation of chronic rejection in rat model system involves modulation of the mTORC1 and mTORC2 pathways. Transplantation 96:782-90
Skelton, T Spencer; Tejpal, Neelam; Gong, Yongquan et al. (2012) Allochimeric molecules and mechanisms in abrogation of cardiac allograft rejection. J Heart Lung Transplant 31:73-84
Lisik, Wojciech; Gong, Yongquan; Tejpal, Neelam et al. (2010) Intragraft gene expression profile associated with the induction of tolerance by allochimeric MHC I in the rat heart transplantation model. Genesis 48:8-19
Skelton, T Spencer; Tejpal, Neelam; Gong, Yongquan et al. (2010) Downregulation of RhoA and changes in T cell cytoskeleton correlate with the abrogation of allograft rejection. Transpl Immunol 23:185-93
Liu, Dahai; Shen, Xiu-Da; Zhai, Yuan et al. (2009) Intragraft selection of the T cell receptor repertoire by class I MHC sequences in tolerant recipients. PLoS One 4:e6076
Lisik, Wojciech; Tejpal, Neelam; Gong, Yongquan et al. (2009) Down regulation of genes involved in T cell polarity and motility during the induction of heart allograft tolerance by allochimeric MHC I. PLoS One 4:e8020
Semiletova, Natalya V; Shen, Xiu-Da; Feldman, Daniel M et al. (2007) Class I MHC allochimeric presentation of composite immunogenic and self epitopes induces tolerance to genetically diverse rat strains. Cell Immunol 248:48-58
Semiletova, N V; Shen, X-D; Feldman, D M et al. (2005) Donor MHC class I peptides in conjunction with self-epitopes induce donor-specific tolerance in a dose-dependent manner but unable to abrogate chronic rejection. Transplant Proc 37:1937-9
Semiletova, Natalya V; Shen, Xiu-Da; Baibakov, Boris et al. (2005) Inhibition of chronic rejection by antibody induced vascular accommodation in fully allogeneic heart allografts. Transplantation 80:1535-40
Liu, D; Shen, X-D; Fang, Z et al. (2005) Identification of early tolerance regulator genes induced by allochimeric therapy using microarray-based genomewide scan. Transplant Proc 37:1942-3