title: Preexisting antiadenoviral immunity and regional myocardial gene transfer: modulation by nitric oxide.
abstract: The utility of adenoviral vectors, currently used in cardiovascular gene transfer protocols, is limited by the brevity of transgene expression and by antiadenoviral immune responses. The effect of preexisting antiadenoviral immunity on intracardiac gene transfer or its modulation by nitric oxide is unknown. Adenoviral vectors, expressing the firefly luciferase gene (AdLuc) or the human nitric oxide synthase 3 (NOS3) gene (AdNOS3), were infused into the great cardiac vein of naive pigs or immunized pigs. Pigs were immunized by intravenous injection of control virus AdRR5 and the resulting neutralizing antibody titers (median, 1:178; p < 0.0001 vs. baseline) were similar to preexisting titers in 54% of randomly selected coronary artery bypass graft patients. In naive animals distribution of transgene expression in the left ventricular free wall was focal. In immunized pigs myocardial luciferase expression 3 days after AdLuc gene transfer was more than 1000-fold lower than in naive pigs, whereas no change in NOS3 transcript levels was detected after AdNOS3 gene transfer. Severe, grade III-IV mononuclear cell infiltration and myocyte apoptosis were observed in four of five AdLuc-infected, immunized animals, compared with low-level inflammation and apoptosis in five of six AdNOS3-infected pigs. Coinfusion of AdLuc and AdNOS3 in immunized pigs resulted in spatially colocalized transgene expression, reduced T cell-mediated inflammation, and myocyte apoptosis and was associated with 200-fold greater median reporter transgene expression levels in the subendocardium (1.0 x 10(3) light units [LU]/mg protein, n = 8, vs. 4.5 x 10(1) LU/mg protein in AdLuc- and AdRR5-coinfected pigs, n = 7, p = 0.02). Preexisting antiadenoviral immunity abrogates myocardial gene expression in pigs and is associated with severe inflammation and myocyte apoptosis. Intracardiac NOS3 gene transfer may reduce these barriers to adenovirus-mediated myocardial gene transfer.
authors.affiliation: Center for Transgene Technology and Gene Therapy, University of Leuven and Flanders Interuniversity Institute of Biotechnology, B-3000 Leuven, Belgium.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Szelid
authors.forename: Peter
authors.initials: P
authors.lastname: Sinnaeve
authors.forename: Pieter
authors.initials: P
authors.lastname: Vermeersch
authors.forename: Hilde
authors.initials: H
authors.lastname: Gillijns
authors.forename: Marijke
authors.initials: M
authors.lastname: Pellens
authors.forename: Veerle
authors.initials: V
authors.lastname: Laurysens
authors.forename: Natascha
authors.initials: N
authors.lastname: Van Pelt
authors.forename: Willem
authors.initials: W
authors.lastname: Flameng
authors.forename: Paul
authors.initials: P
authors.lastname: Sergeant
authors.forename: Paul
authors.initials: P
authors.lastname: Herijgers
authors.forename: Peter
authors.initials: P
authors.lastname: Pokreisz
authors.forename: Anton-Jan
authors.initials: AJ
authors.lastname: Van Zonneveld
authors.forename: Erik
authors.initials: E
authors.lastname: Verbeken
authors.forename: Desire
authors.initials: D
authors.lastname: Collen
authors.forename: Stefan
authors.initials: S
authors.lastname: Janssens
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000276:immunology*; D005786:Gene Expression Regulation / Q000276:immunology; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000276:immunology*; D007113:Immunity, Innate; D009205:Myocarditis / Q000235:genetics / Q000276:immunology / Q000628:therapy; D009206:Myocardium / Q000276:immunology* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D013552:Swine
chemical_list: D009569:Nitric Oxide