title: Adenoviral-mediated gene transfer into the canine brain in vivo.
abstract: OBJECTIVE
  Glioblastoma multiforme (GBM) is a devastating brain tumor for which there is no cure. Adenoviral-mediated transfer of conditional cytotoxic (herpes simplex virus [HSV] 1-derived thymidine kinase [TK]) and immunostimulatory (Fms-like tyrosine kinase 3 ligand [Flt3L]) transgenes elicited immune-mediated long-term survival in a syngeneic intracranial GBM model in rodents. However, the lack of a large GBM animal model makes it difficult to predict the outcome of therapies in humans. Dogs develop spontaneous GBM that closely resemble the human disease; therefore, they constitute an excellent large animal model. We assayed the transduction efficiency of adenoviral vectors (Ads) encoding beta-galactosidase (betaGal), TK, and Flt3L in J3T dog GBM cells in vitro and in the dog brain in vivo.
  
  
  METHODS
  J3T cells were infected with Ads (30 plaque-forming units/cell; 72 h) encoding betaGal (Ad-betaGal), TK (Ad-TK), or Flt3L (Ad-Flt3L). We determined transgene expression by immunocytochemistry, betaGal activity, Flt3L enzyme-linked immunosorbent assay, and TK-induced cell death. Ads were also injected intracranially into the parietal cortex of healthy dogs. We determined cell-type specific transgene expression and immune cell infiltration.
  
  
  RESULTS
  Adenoviral-mediated gene transfer of HSV1-TK, Flt3L, and betaGal was detected in dog glioma cells in vitro (45% transduction efficiency) and in the dog brain in vivo (10-mm area transduced surrounding each injection site). T cells and macrophages/activated microglia infiltrated the injection sites. Importantly, no adverse clinical or neuropathological side effects were observed.
  
  
  CONCLUSIONS
  We demonstrate effective adenoviral-mediated gene transfer into the brain of dogs in vivo and support the use of these vectors to develop an efficacy trial for canine GBM as a prelude to human trials.
authors.affiliation: Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.
authors.forename: Marianela
authors.initials: M
authors.lastname: Candolfi
authors.forename: Kurt M
authors.initials: KM
authors.lastname: Kroeger
authors.forename: G Elizabeth
authors.initials: GE
authors.lastname: Pluhar
authors.forename: Josee
authors.initials: J
authors.lastname: Bergeron
authors.forename: Mariana
authors.initials: M
authors.lastname: Puntel
authors.forename: James F
authors.initials: JF
authors.lastname: Curtin
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: McNiel
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Freese
authors.forename: John R
authors.initials: JR
authors.lastname: Ohlfest
authors.forename: Peter
authors.initials: P
authors.lastname: Moore
authors.forename: Pedro R
authors.initials: PR
authors.lastname: Lowenstein
authors.forename: Maria G
authors.initials: MG
authors.lastname: Castro
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D001921:Brain / Q000502:physiology*; D001932:Brain Neoplasms / Q000235:genetics; D004195:Disease Models, Animal; D004285:Dogs; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D014407:Tumor Cells, Cultured