A Fas-based suicide switch in human T cells for the treatment of graft-versus-host disease.
Graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation. One strategy to treat GVHD is to equip donor T cells with a conditional suicide mechanism that can be triggered when GVHD occurs. The herpes simplex virus thymidine kinase (HSV-tk)/ganciclovir system used clinically has several limitations, including immunogenicity and cell cycle dependence. An alternative switch based on chemically inducible apoptosis was designed and evaluated. A chimeric human protein was expressed comprising an extracellular marker (DeltaLNGFR), the Fas intracellular domain, and 2 copies of an FK506-binding protein (FKBP). Primary human T lymphocytes retrovirally transduced with this construct could be purified to homogeneity using immunomagnetic beads. Genetic integrity of the construct was ensured by redesigning repetitive sequences. Transduced T cells behaved indistinguishably from untransduced cells, retaining the ability to mount a specific antiallogeneic immune response. However, they rapidly underwent apoptosis with the addition of subnanomolar concentrations of AP1903, a bivalent "dimerizer" drug that binds FKBP and induces Fas cross-linking. A single 2-hour treatment eliminated approximately 80% of T cells, and multiple exposures induced further apoptosis. T cells were eliminated regardless of their proliferation state, suggesting that the AP1903/Fas system, which contains only human components, is a promising alternative to HSV-tk for treating GVHD.
ARIAD Gene Therapeutics, Cambridge, MA 02139, USA.
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Thomis
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Marktel
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Bonini
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Traversari
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Gilman
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Bordignon
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Clackson
D017209:Apoptosis / Q000187:drug effects; D016026:Bone Marrow Transplantation; D003432:Cross-Linking Reagents / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015321:Gene Rearrangement / Q000187:drug effects; D006086:Graft vs Host Disease / Q000517:prevention & control / Q000628:therapy*; D006801:Humans; D018189:Immunomagnetic Separation; D008213:Lymphocyte Activation / Q000187:drug effects; D009930:Organic Chemicals; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000627:therapeutic use; D012190:Retroviridae / Q000235:genetics; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014161:Transduction, Genetic / Q000379:methods; D019076:Transgenes / Q000235:genetics; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use*
D003432:Cross-Linking Reagents; D009930:Organic Chemicals; D011993:Recombinant Fusion Proteins; D019014:fas Receptor; D022021:Tacrolimus Binding Proteins; C423866:AP 1903 reagent