Abstract
A granulocyte/macrophage colony-stimulating factor (GM-CSF)-Pseudomonas exotoxin (PE) 40 fusion protein was constructed for potential use in the treatment of myeloid leukaemias, as a conditioning agent prior to allogeneic bone marrow transplantation or for ex vivo purging of malignant cells prior to autologous bone marrow transplantation. The GM-CSF-PE40 fusion protein successfully binds to the GM-CSF receptor and is capable of initiating a mitogenic signal similar to native GM-CSF in the GM-CSF-dependent TF1 cell line. The toxin component also appears to be fully functional as determined by an in vitro adenosine diphosphate-ribosylation assay. The GM-CSF-PE40 fusion protein, however, was not cytotoxic to a number of myeloid leukaemia cell lines. It is suggested that the mechanism of internalization of the GM-CSF receptor is not appropriate for the translocation of PE to the cytosol where it can fulfil its cytotoxic potential.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ADP Ribose Transferases*
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Adenosine Diphosphate Ribose / metabolism
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Bacterial Toxins / genetics
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Bacterial Toxins / metabolism
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Bacterial Toxins / pharmacology*
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Base Sequence
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Biological Transport, Active
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Bone Marrow Purging
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Bone Marrow Transplantation
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Cell Death / drug effects
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DNA Primers / genetics
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Exotoxins / genetics
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Exotoxins / metabolism
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Exotoxins / pharmacology*
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Granulocyte-Macrophage Colony-Stimulating Factor / genetics
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Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
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Granulocyte-Macrophage Colony-Stimulating Factor / pharmacology*
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Humans
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Immunotoxins / genetics
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Immunotoxins / metabolism
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Immunotoxins / pharmacology*
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In Vitro Techniques
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Leukemia, Myeloid / therapy
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Polymerase Chain Reaction
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Pseudomonas aeruginosa Exotoxin A
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Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Recombinant Fusion Proteins / pharmacology
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Transplantation Conditioning
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Tumor Cells, Cultured
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Virulence Factors*
Substances
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Bacterial Toxins
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DNA Primers
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Exotoxins
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Immunotoxins
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Receptors, Granulocyte-Macrophage Colony-Stimulating Factor
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Recombinant Fusion Proteins
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Virulence Factors
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Adenosine Diphosphate Ribose
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Granulocyte-Macrophage Colony-Stimulating Factor
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ADP Ribose Transferases