title: Oncolytic effects of a novel influenza A virus expressing interleukin-15 from the NS reading frame.
abstract: Oncolytic influenza A viruses with deleted NS1 gene (delNS1) replicate selectively in tumour cells with defective interferon response and/or activated Ras/Raf/MEK/ERK signalling pathway. To develop a delNS1 virus with specific immunostimulatory properties, we used an optimised technology to insert the interleukin-15 (IL-15) coding sequence into the viral NS gene segment (delNS1-IL-15). DelNS1 and delNS1-IL-15 exerted similar oncolytic effects. Both viruses replicated and caused caspase-dependent apoptosis in interferon-defective melanoma cells. Virus replication was required for their oncolytic activity. Cisplatin enhanced the oncolytic activity of delNS1 viruses. The cytotoxic drug increased delNS1 replication and delNS1-induced caspase-dependent apoptosis. Interference with MEK/ERK signalling by RNAi-mediated depletion or the MEK inhibitor U0126 did not affect the oncolytic effects of the delNS1 viruses. In oncolysis sensitive melanoma cells, delNS1-IL-15 (but not delNS1) infection resulted in the production of IL-15 levels ranging from 70 to 1140 pg/mL in the cell culture supernatants. The supernatants of delNS1-IL-15-infected (but not of delNS1-infected) melanoma cells induced primary human natural killer cell-mediated lysis of non-infected tumour cells. In conclusion, we constructed a novel oncolytic influenza virus that combines the oncolytic activity of delNS1 viruses with immunostimulatory properties through production of functional IL-15. Moreover, we showed that the oncolytic activity of delNS1 viruses can be enhanced in combination with cytotoxic anti-cancer drugs.
authors.affiliation: Institut für Medizinische Virologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
authors.forename: Marijke
authors.initials: M
authors.lastname: van Rikxoort
authors.forename: Martin
authors.initials: M
authors.lastname: Michaelis
authors.forename: Markus
authors.initials: M
authors.lastname: Wolschek
authors.forename: Thomas
authors.initials: T
authors.lastname: Muster
authors.forename: Andrej
authors.initials: A
authors.lastname: Egorov
authors.forename: Joachim
authors.initials: J
authors.lastname: Seipelt
authors.forename: Hans Wilhelm
authors.initials: HW
authors.lastname: Doerr
authors.forename: Jindrich
authors.initials: J
authors.lastname: Cinatl
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D002945:Cisplatin / Q000494:pharmacology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D017353:Gene Deletion; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000254:growth & development; D019409:Interleukin-15 / Q000235:genetics* / Q000378:metabolism; D008545:Melanoma / Q000235:genetics / Q000473:pathology / Q000821:virology; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D050504:Oncolytic Viruses / Q000235:genetics* / Q000254:growth & development; D034622:RNA Interference; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000970:Antineoplastic Agents; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D019409:Interleukin-15; D017361:Viral Nonstructural Proteins; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020169:Caspases; D002945:Cisplatin