Abstract

Inhibition of recombinant (r) adenovirus (Ad)-induced, NFkappaB-dependent dendritic cell (DC) maturation by NFkappaB decoy oligodeoxyribonucleotides (ODN) permits functional expression of a potent immunosuppressive transgene product (CTLA4Ig). These cells traffic to T cell areas of host secondary lymphoid tissue and markedly prolong organ allograft survival in the absence of systemic levels of CTLA4Ig. We hypothesize that these gene engineered DC can promote transplant tolerance by mediating apoptotic death of allospecific T cells. We have four Specific Aims:
Aim I will analyze the impact of the stably immature, gene-engineered DC on alloreactive T cell apoptosis. We will test whether gene-engineered myeloid DC (MDC) and """"""""lymphoid-related"""""""" DC (LDC), which differ in their interactions with T cells, have equal potential to mediate apoptosis of alloactivated T cells, whether Th1 and Th2 cells are equally susceptible, and the extent to which memory CD4 + T cells are also killed.
In Aim II, we shall ascertain the death regulatory pathways and type of apoptosis induced by these gene engineered DC. We shall examine the contribution of the Fas:FasL and TRAIL:TRAILR pathways, key T cell survival factors (Bcl-2/BClxL) and the role of passive versus active cell death.
In Aim III, we will evaluate the fate and function of the gene engineered DC, and their capacity to delete alloreactive T cells in vivo, by quantitative assessment of both the proliferation and apoptosis of CD4 + and CD8 + T cells. Mice with defective passive or active T cell death pathways will be used to evaluate the requirement of these pathways for T cell deletion. We shall also determine whether Ag-specific T cells are deleted selectively.
In AIM I V, we will determine the ability of the gene engineered DC to promote donor-specific transplant tolerance and its dependence on T cell apoptosis. We will evaluate host immunocompetence and anti-donor reactivity including graft integrity, at times remote from administration of the gene engineered DC. The results will provide new insight into the potential of gene engineered DC for therapy of organ transplant rejection.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI041011-09
Application #
7057264
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Macchiarini, Francesca
Project Start
1997-05-01
Project End
2008-04-30
Budget Start
2006-05-01
Budget End
2008-04-30
Support Year
9
Fiscal Year
2006
Total Cost
$258,319
Indirect Cost

  Institution

Name
University of Pittsburgh
Department
Surgery
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213

  Publications

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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