title: Pro-inflammatory cytokine/chemokine production by reovirus treated melanoma cells is PKR/NF-κB mediated and supports innate and adaptive anti-tumour immune priming.
abstract: BACKGROUND
  As well as inducing direct oncolysis, reovirus treatment of melanoma is associated with activation of innate and adaptive anti-tumour immune responses.
  
  
  RESULTS
  Here we characterise the effects of conditioned media from reovirus-infected, dying human melanoma cells (reoTCM), in the absence of live virus, to address the immune bystander potential of reovirus therapy. In addition to RANTES, IL-8, MIP-1α and MIP-1β, reovirus-infected melanoma cells secreted eotaxin, IP-10 and the type 1 interferon IFN-β. To address the mechanisms responsible for the inflammatory composition of reoTCM, we show that IL-8 and IFN-β secretion by reovirus-infected melanoma cells was associated with activation of NF-κB and decreased by pre-treatment with small molecule inhibitors of NF-κB and PKR; specific siRNA-mediated knockdown further confirmed a role for PKR. This pro-inflammatory milieu induced a chemotactic response in isolated natural killer (NK) cells, dendritic cells (DC) and anti-melanoma cytotoxic T cells (CTL). Following culture in reoTCM, NK cells upregulated CD69 expression and acquired greater lytic potential against tumour targets. Furthermore, melanoma cell-loaded DC cultured in reoTCM were more effective at priming adaptive anti-tumour immunity.
  
  
  CONCLUSIONS
  These data demonstrate that the PKR- and NF-κB-dependent induction of pro-inflammatory molecules that accompanies reovirus-mediated killing can recruit and activate innate and adaptive effector cells, thus potentially altering the tumour microenvironment to support bystander immune-mediated therapy as well as direct viral oncolysis.
authors.affiliation: Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK.
authors.forename: Lynette
authors.initials: L
authors.lastname: Steele
authors.forename: Fiona
authors.initials: F
authors.lastname: Errington
authors.forename: Robin
authors.initials: R
authors.lastname: Prestwich
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ilett
authors.forename: Kevin
authors.initials: K
authors.lastname: Harrington
authors.forename: Hardev
authors.initials: H
authors.lastname: Pandha
authors.forename: Matt
authors.initials: M
authors.lastname: Coffey
authors.forename: Peter
authors.initials: P
authors.lastname: Selby
authors.forename: Richard
authors.initials: R
authors.lastname: Vile
authors.forename: Alan
authors.initials: A
authors.lastname: Melcher
mesh_terms: D056704:Adaptive Immunity / Q000187:drug effects / Q000276:immunology; D045744:Cell Line, Tumor; D018925:Chemokines / Q000096:biosynthesis* / Q000378:metabolism; D002633:Chemotaxis / Q000187:drug effects; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007109:Immunity / Q000187:drug effects / Q000276:immunology*; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology; D018836:Inflammation Mediators / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008545:Melanoma / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D016328:NF-kappa B / Q000378:metabolism*; D010641:Phenotype; D012087:Reoviridae / Q000187:drug effects / Q000276:immunology*; D012088:Reoviridae Infections / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D019892:eIF-2 Kinase / Q000378:metabolism*
chemical_list: D018925:Chemokines; D017077:Culture Media, Conditioned; D018836:Inflammation Mediators; D016328:NF-kappa B; D019892:eIF-2 Kinase