Despite recent advances in immunosuppresive drug therapy, rejection remains the principal cause of the organ transplant failure. In addition, serious side effects such as life-threatening infection or malignancy are often associated with chronic immunosuppression. The ability to induce functional, donor antigen-specific T cell tolerance with the reduction or (preferably) the elimination of systemic immunosuppressive drug treatment is a primary goal for more effective and safer organ transplantation. Recently, we and others have demonstrated the induciton of anergy in T cells, following """"""""incomplete"""""""" or """"""""inappropriate"""""""" activation by antigen presenting cells (APC). Our data show that dendritic cells (DC) lacking sufficient cell surface expression of costimulatory molecules for naive T cell activation, e.g. B7-1 (CD86), induce alloantigen=specific anergy. Moreover, we have reported that in mice, costimulatory molecule-deficient DC can promote the survival both of cell and organ allografts in otherwise non-immunosuppressed hosts. We also present evidence that the cytokine microenvironment to which DC are pre-exposed or that is present during T cell priming dictates the nature and magnitude of the resultant immune response. Thus, the """"""""immunosuppressive"""""""" cytokines viral (v) interleukin-10 (vIL-10) and transforming growth factor-beta (TGFbeta) can markedly inhibit the capacity of DC to activate naive T cells. In addition, we have shown for the first time that DC induced to produce nitric oxide (NO) or that express Fas (CD95) ligand can induce programmed cell death (apoptosis) in alloactivated T cells. In this study, we propose to AIM I: genetically modify DC to express """"""""immunosuppressive"""""""" molecules (subsequently identified in parentheses) that I) reduce the expression level of APC-associated costimulatory molecules (vIL-10, TGF-beta,CTLA44-Ig), 2) skew the balance of the alloantigen-specific T cell response towards a T helper 2 response (IFN-gammadR, EBI-3, CTLA4-Ig), or 3) promote the deletion (apoptosis) of alloantigen-specific T cell clones (Fas-L, iNOS, TRAIL);
AIM II; determine the impact of gene-engineered DC on in vitro models of anti-allograft immunity;
AIM III : by providing experimental organ (heart) transplant recipient with allogeneic DC modified to express one or more of these transgenes, we hope to enhance graft survival. Accrual of positive results from these animal studies will provide a basis for a trial of gene- engineered DC therapy in patients receiving organ transplants.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI041011-03
Application #
2887400
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Kehn, Patricia J
Project Start
1997-05-01
Project End
2002-04-30
Budget Start
1999-05-01
Budget End
2000-04-30
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Surgery
Type
Schools of Medicine
DUNS #
053785812
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Turnquist, Hth R; Fischer, Ryan T; Thomson, Angus W (2010) Pharmacological modification of dendritic cells to promote their tolerogenicity in transplantation. Methods Mol Biol 595:135-48
Fischer, Ryan; Turnquist, Heth R; Taner, Timucin et al. (2009) Use of rapamycin in the induction of tolerogenic dendritic cells. Handb Exp Pharmacol :215-32
Turnquist, Heth R; Sumpter, Tina L; Tsung, Allan et al. (2008) IL-1beta-driven ST2L expression promotes maturation resistance in rapamycin-conditioned dendritic cells. J Immunol 181:62-72
Turnquist, Heth R; Thomson, Angus W (2008) Taming the lions: manipulating dendritic cells for use as negative cellular vaccines in organ transplantation. Curr Opin Organ Transplant 13:350-7
Ikeguchi, Ryosuke; Sacks, Justin M; Unadkat, Jignesh V et al. (2008) Long-term survival of limb allografts induced by pharmacologically conditioned, donor alloantigen-pulsed dendritic cells without maintenance immunosuppression. Transplantation 85:237-46
Aiello, Sistiana; Cassis, Paola; Cassis, Linda et al. (2007) DnIKK2-transfected dendritic cells induce a novel population of inducible nitric oxide synthase-expressing CD4+CD25- cells with tolerogenic properties. Transplantation 83:474-84
Sumpter, Tina L; Abe, Masanori; Tokita, Daisuke et al. (2007) Dendritic cells, the liver, and transplantation. Hepatology 46:2021-31
Turnquist, Heth R; Raimondi, Giorgio; Zahorchak, Alan F et al. (2007) Rapamycin-conditioned dendritic cells are poor stimulators of allogeneic CD4+ T cells, but enrich for antigen-specific Foxp3+ T regulatory cells and promote organ transplant tolerance. J Immunol 178:7018-31
Taieb, Aurele; Breitinger, Jeremy J; Unadkat, Jignesh V et al. (2007) Intrinsic ability of GM+IL-4 but not Flt3L-induced rat dendritic cells to promote allogeneic T cell hyporesponsiveness. Clin Immunol 123:176-89
Raimondi, Giorgio; Turner, Michael S; Thomson, Angus W et al. (2007) Naturally occurring regulatory T cells: recent insights in health and disease. Crit Rev Immunol 27:61-95

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