Adenoviral mediated gene transfer into the dog brain in vivo

CANDOLFI; KROEGER; PLUHAR; BERGERON; PUNTEL; CURTIN; MCNIEL; FREESE; OHLFEST; MOORE; LOWENSTEIN; CASTRO

NEUROSURGERY.

LIPPINCOTT WILLIAMS & WILKINS

Año: 2007 p. 167 - 178

0148-396X

OBJECTIVE: Glioblastoma multiforme (GBM) is a devastating brain tumor for whichthere is no cure. Adenoviral-mediated transfer of conditional cytotoxic (herpes simplexvirus [HSV] 1-derived thymidine kinase [TK]) and immunostimulatory (Fms-like tyrosinekinase 3 ligand [Flt3L]) transgenes elicited immune-mediated long-term survival in asyngeneic intracranial GBM model in rodents. However, the lack of a large GBM animalmodel makes it difficult to predict the outcome of therapies in humans. Dogsdevelop spontaneous GBM that closely resemble the human disease; therefore, theyconstitute an excellent large animal model. We assayed the transduction efficiency ofadenoviral vectors (Ads) encoding β-galactosidase (βGal), TK, and Flt3L in J3T dog GBMcells in vitro and in the dog brain in vivo.METHODS: J3T cells were infected with Ads (30 plaque-forming units/cell; 72 h) encodingβGal (Ad-βGal), TK (Ad-TK), or Flt3L (Ad-Flt3L). We determined transgene expressionby immunocytochemistry, βGal activity, Flt3L enzyme-linked immunosorbent assay,and TK-induced cell death. Ads were also injected intracranially into the parietal cortexof healthy dogs. We determined cell-type specific transgene expression and immunecell infiltration.RESULTS: Adenoviral-mediated gene transfer of HSV1-TK, Flt3L, and βGal was detectedin dog glioma cells in vitro (45% transduction efficiency) and in the dog brain in vivo(10-mm2 area transduced surrounding each injection site). T cells and macrophages/activatedmicroglia infiltrated the injection sites. Importantly, no adverse clinical or neuropathologicalside effects were observed.CONCLUSION:We demonstrate effective adenoviral-mediated gene transfer into thebrain of dogs in vivo and support the use of these vectors to develop an efficacy trial forcanine GBM as a prelude to human trials.