title: Ex vivo inhibition of NF-kappaB signaling in alloreactive T-cells prevents graft-versus-host disease.
abstract: The ex vivo induction of alloantigen-specific hyporesponsiveness by costimulatory pathway blockade or exposure to immunoregulatory cytokines has been shown to inhibit proliferation, IL-2 production, and the graft-versus-host disease (GVHD) capacity of adoptively transferred T-cells. We hypothesized that inhibition of the intracellular NF-kappaB pathway in alloreactive T-cells, which is critical for T-cell activation events including IL-2 transcription, could lead to alloantigen hyporesponsiveness and loss of GVHD capacity. We demonstrate that treatment of mixed lymphocyte reaction (MLR) cultures with PS1145, a potent inhibitor of NF-kappaB activation, can induce T-cell hyporesponsiveness to alloantigen in primary and secondary responses while preserving in vitro responses to potent mitogenic stimulation. GVHD lethality in recipients of ex vivo PS1145-treated cells was profoundly inhibited. Parking of control or PS1145-treated MLR cells in syngeneic Rag(-/-) recipients resulted in intact contact hypersensitivity (CHS) responses. However, GVHD lethality capacity also was restored, suggesting that lymphopenic expansion uncoupled alloantigen hyporesponsiveness. These results indicate that the NF-kappaB pathway is a critical regulator of alloresponses and provide a novel small molecule inhibitor based approach that is effective in preventing early posttransplant GVHD lethality but that also permits donor T-cell responses to recover after a period of lymphopenic expansion.
authors.affiliation: Department of Pediatrics, Division of Bone Marrow Transplantation, University of Minnesota Cancer Center, Minneapolis, MN, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Shaughnessy
authors.forename: C
authors.initials: C
authors.lastname: Vogtenhuber
authors.forename: K
authors.initials: K
authors.lastname: Sun
authors.forename: R
authors.initials: R
authors.lastname: Sitcheran
authors.forename: A S
authors.initials: AS
authors.lastname: Baldwin
authors.forename: W J
authors.initials: WJ
authors.lastname: Murphy
authors.forename: L
authors.initials: L
authors.lastname: Dang
authors.forename: B
authors.initials: B
authors.lastname: Jaffee
authors.forename: E
authors.initials: E
authors.lastname: Palmer
authors.forename: J S
authors.initials: JS
authors.lastname: Serody
authors.forename: B R
authors.initials: BR
authors.lastname: Blazar
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006086:Graft vs Host Disease / Q000276:immunology* / Q000378:metabolism*; D006575:Heterocyclic Compounds, 3-Ring / Q000494:pharmacology; D007519:Isoantigens / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051379:Mice; D018448:Models, Immunological; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*
chemical_list: D006575:Heterocyclic Compounds, 3-Ring; D007519:Isoantigens; D016328:NF-kappa B; C456319:PS1145; D011725:Pyridines