title: Preclinical validation: LV/IL-12 transduction of patient leukemia cells for immunotherapy of AML.
abstract: Interleukin-12 (IL-12) is a potent cytokine that may be harnessed to treat cancer. To date, nearly 100 IL-12-based clinical trials have been initiated worldwide. Yet systemic administration of IL-12 is toxic. Different strategies are being developed to reduce such toxicities by restricting IL-12 distribution. Our previous studies employed lentivector-mediated expression of murine IL-12 in tumor cells and demonstrated effective protection in both mouse leukemia and solid tumor challenge models. In this study, we carried out preclinical validation studies using a novel lentivector to engineer expression of human IL-12 in acute myeloid leukemia blast cells isolated from 21 patients. Acute myeloid leukemia cells were transduced with a bicistronic lentivector that encodes the human IL-12 cDNA as a fusion, as well as a LNGFR (ΔLNGFR)/mutant thymidylate kinase cassette as a marking and cell-fate control element. A range of 20-70% functional transduction efficiencies was achieved. Transduced acute myeloid leukemia cells produced bioactive IL-12 protein and displayed dose-dependent sensitivity to the prodrug 3'-azido-3'-deoxythymidine.In vitroimmortalization assays using transduced mouse hematopoietic stem cells demonstrated minimal genotoxic risk from our IL-12 vector. Scale-up transduction and cell processing was subsequently validated in a GMP facility to support our (now approved) Clinical Trial Application (CTA).
authors.affiliation: University Health Network , Toronto, Ontario, Canada.
authors.forename: Ju
authors.initials: J
authors.lastname: Huang
authors.affiliation: University Health Network , Toronto, Ontario, Canada.
authors.forename: Yuanfeng
authors.initials: Y
authors.lastname: Liu
authors.affiliation: University Health Network , Toronto, Ontario, Canada.
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Au
authors.affiliation: University Health Network, Toronto, Ontario, Canada; Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Dwayne L
authors.initials: DL
authors.lastname: Barber
authors.affiliation: University Health Network , Toronto, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Arruda
authors.affiliation: Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Axel
authors.initials: A
authors.lastname: Schambach
authors.affiliation: Institute of Experimental Hematology, Hannover Medical School , Hannover, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Rothe
authors.affiliation: University Health Network, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Minden
authors.affiliation: University Health Network, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Department of Immunology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Paige
authors.affiliation: University Health Network, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Medin