title: High-throughput screening identifies compounds that enhance lentiviral transduction.
abstract: A difficulty in the field of gene therapy is the need to increase the susceptibility of hematopoietic stem cells (HSCs) to ex vivo genetic manipulation. To overcome this obstacle a high-throughput screen was performed to identify compounds that could enhance the transduction of target cells by lentiviral vectors. Of the 1280 compounds initially screened using the myeloid-erythroid-leukemic K562 cell line, 30 were identified as possible enhancers of viral transduction. Among the positive hits were known enhancers of transduction (camptothecin, etoposide and taxol), as well as the previously unidentified phorbol 12-myristate 13-acetate (PMA). The percentage of green fluorescent protein (GFP)-positive-expressing K562 cells was increased more than fourfold in the presence of PMA. In addition, the transduction of K562 cells with a lentiviral vector encoding fVIII was four times greater in the presence of PMA as determined by an increase in the levels of provirus in genetically modified cells. PMA did not enhance viral transduction of all cell types (for example, sca-1(+) mouse hematopoietic cells) but did enhance viral transduction of human bone marrow-derived CD34(+) cells. Notably, the percentage of GFP-positive CD34(+) cells was increased from 7% in the absence of PMA to greater than 22% in the presence of 1 nM PMA. PMA did not affect colony formation of CD34(+) cells or the expression of the hematopoietic markers CD34 and CD45. These data demonstrate that high-throughput screening can be used to identify compounds that increase the transduction efficiency of lentiviral vectors, identifying PMA as a potential enhancer of lentiviral HSC transduction.
authors.affiliation: 1] Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA [2] Graduate Program in Molecular and Systems Pharmacology, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Johnston
authors.affiliation: Expression Therapeutics, LLC, Tucker, GA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Denning
authors.affiliation: 1] Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA [2] Graduate Program in Molecular and Systems Pharmacology, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Moot
authors.affiliation: Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: D
authors.initials: D
authors.lastname: Whitehead
authors.affiliation: Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Shields
authors.affiliation: Wallace H Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, GA, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Le Doux
authors.affiliation: Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Doering
authors.affiliation: Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Spencer
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D045744:Cell Line, Tumor; D005576:Colforsin / Q000494:pharmacology; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D041681:NIH 3T3 Cells; D020123:Sirolimus / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D014161:Transduction, Genetic; D020298:U937 Cells
chemical_list: D018952:Antigens, CD34; D049452:Green Fluorescent Proteins; D005576:Colforsin; C016658:phorbolol myristate acetate; D013755:Tetradecanoylphorbol Acetate; D020123:Sirolimus; D002166:Camptothecin