title: Quantitative, noninvasive, in vivo longitudinal monitoring of gene expression in the brain by co-AAV transduction with a PET reporter gene.
abstract: In vivo imaging of vector transgene expression would be particularly valuable for repetitive monitoring of therapy in the brain, where invasive tissue sampling is contraindicated. We evaluated adeno-associated virus vector expression of a dopamine-2 receptor (D2R) mutant (D2R80A) by positron emission tomography in the brains of mice and cats. D2R80A is inactivated for intracellular signaling and binds subphysiologic amounts of the radioactive [(18)F]-fallypride analog of dopamine. The [(18)F]-fallypride signal bound to D2R80A in the injection site was normalized to the signal from endogenous D2R in the striatum and showed stable levels of expression within individual animals. A separate adeno-associated virus type 1 vector with identical gene expression control elements, expressing green fluorescent protein or a therapeutic gene, was coinjected with the D2R80A vector at equal doses into specific sites. Both transgenes had similar levels of gene expression by immunohistochemistry, in situ hybridization, and quantitative PCR assays, demonstrating that D2R80A is a faithful surrogate measure for expression of a gene of interest. This dual vector approach allows the D2R80A gene to be used with any therapeutic gene and to be injected into a single site for monitoring while the therapeutic gene can be distributed more widely as needed in each disease.
authors.affiliation: Research Institute of Children's Hospital of Philadelphia , Philadelphia, Pennsylvania, USA.
authors.forename: Sea Young
authors.initials: SY
authors.lastname: Yoon
authors.affiliation: Research Institute of Children's Hospital of Philadelphia , Philadelphia, Pennsylvania, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Gay-Antaki
authors.affiliation: Department of Radiology,Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania, USA ; Current address: Deccan Institute of Chemical Technology , Maharashtra, India.
authors.forename: Datta E
authors.initials: DE
authors.lastname: Ponde
authors.affiliation: Department of Radiology,Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania, USA.
authors.forename: Harish
authors.initials: H
authors.lastname: Poptani
authors.affiliation: W.F. Goodman Center for Comparative Medical Genetics, School of Veterinary Medicine, University of Pennsylvania , Philadelphia, Pennsylvania, USA.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Vite
authors.affiliation: Research Institute of Children's Hospital of Philadelphia , Philadelphia, Pennsylvania, USA ; W.F. Goodman Center for Comparative Medical Genetics, School of Veterinary Medicine, University of Pennsylvania , Philadelphia, Pennsylvania, USA ; Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Wolfe