title: The use of lentiviral vectors in gene therapy of leukemia: combinatorial gene delivery of immunomodulators into leukemia cells by state-of-the-art vectors.
abstract: Our goal is to develop cell vaccines against leukemia cells, genetically modified to express molecules with potent immune-stimulatory capacities. Pre-clinical evaluation of this approach in murine models has demonstrated efficient anti-leukemic responses with the expression of immunomodulators, in particular GM-CSF and CD80, in irradiated cell vaccines. We have previously shown efficient insertion of GM-CSF and CD80 genes into primary human leukemia cells with the use of second and third generation self-inactivating (SIN) lentiviral vectors (Blood 96 (2000), 1317; Leukemia 16 (2002), 1645). The advantages of lentiviral vectors for development of autologous leukemia cell vaccines include: (1) efficient and consistent gene delivery; (2) high levels of transgene expression; (3) persistent expression of the transduced gene; (4) no viral proteins, as only the transduced gene is expressed; (5) no undesirable cytotoxic effects, and; (6) simplicity of use [leukemia cells are exposed to vector(s) only once]. In this work, we evaluated the insertion of the central polypurine tract and the central termination sequence into a SIN lentiviral vector encoding for GM-CSF and CD80, which significantly enhanced the transduction efficiency of primary leukemia cells and provided higher levels of GM-CSF and CD80 co-expression. We also demonstrate a methodology to deliver simultaneously a combination of immunomodulatory molecules (GM-CSF, CD80, IL-4, and CD40L) to activate different pathways of immune stimulation. Therefore, lentiviral vectors offer a simple, versatile, and reliable approach for engineering leukemic cells for use as cell vaccines.
authors.affiliation: Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA. stripeck@usc.edu
authors.forename: Renata
authors.initials: R
authors.lastname: Stripecke
authors.forename: Richard C
authors.initials: RC
authors.lastname: Koya
authors.forename: Huy Q
authors.initials: HQ
authors.lastname: Ta
authors.forename: Nori
authors.initials: N
authors.lastname: Kasahara
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Levine
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000235:genetics; D018122:B7-1 Antigen / Q000235:genetics; D023201:CD40 Ligand / Q000008:administration & dosage / Q000235:genetics; D004338:Drug Combinations; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000235:genetics; D006801:Humans; D015847:Interleukin-4 / Q000008:administration & dosage / Q000235:genetics; D016086:Lentivirus / Q000235:genetics*; D007951:Leukemia, Myeloid / Q000473:pathology / Q000628:therapy*; D014161:Transduction, Genetic
chemical_list: D000276:Adjuvants, Immunologic; D018122:B7-1 Antigen; D004338:Drug Combinations; D023201:CD40 Ligand; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor