Protein replacement by receptor-mediated endocytosis corrects the sensitivity of Fanconi anemia group C cells to mitomycin C.
Current methods for direct gene transfer into hematopoietic cells are inefficient. Here we show that functional complementation of Fanconi anemia (FA) group C cells by protein replacement can be as efficacious as by transfection with wild-type FAC cDNA. We expressed a chimeric protein (called His-ILFAC) consisting of the mature coding portion of gibbon interleukin-3 (IL-3) and full-length FAC in Escherichia coli. The purified bacterial protein is internalized by hematopoietic cells via IL-3 receptors. The intracellular half-life of His-ILFAC is approximately 60 minutes, which is comparable to that of the transgene-encoded FAC protein. In this cell-culture model His-ILFAC completely corrects the sensitivity of FA group C cells to mitomycin C, but it has no effect on FA cells that belong to complementation groups A and B. We suggest that receptor-mediated endocytosis of cytokine-fusion proteins may be of general use to deliver macromolecules into hematopoietic progenitor cells.
Youssoufian
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Department of Molecular and Human Genetics and the Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA. hagopy@bcm.tmc.edu
Kruyt
F A
FA
Li
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D000818:Animals; D018797:Cell Cycle Proteins; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004268:DNA-Binding Proteins; D004705:Endocytosis / Q000187:drug effects / Q000235:genetics*; D005199:Fanconi Anemia / Q000235:genetics / Q000473:pathology* / Q000628:therapy*; D052218:Fanconi Anemia Complementation Group C Protein; D051856:Fanconi Anemia Complementation Group Proteins; D018014:Gene Transfer Techniques; D006639:Histidine / Q000235:genetics; D006801:Humans; D006922:Hylobates; D007377:Interleukin-3 / Q000235:genetics; D016685:Mitomycin / Q000494:pharmacology*; D009687:Nuclear Proteins; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D016185:Receptors, Interleukin-3 / Q000096:biosynthesis / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000138:chemical synthesis / Q000378:metabolism / Q000502:physiology*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C497651:FANCC protein, human; D052218:Fanconi Anemia Complementation Group C Protein; D051856:Fanconi Anemia Complementation Group Proteins; D007377:Interleukin-3; D009687:Nuclear Proteins; D011506:Proteins; D011956:Receptors, Cell Surface; D016185:Receptors, Interleukin-3; D011993:Recombinant Fusion Proteins; D006639:Histidine; D016685:Mitomycin