Long-term luciferase expression monitored by bioluminescence imaging after adeno-associated virus-mediated fetal gene delivery in rhesus monkeys (Macaca mulatta)

• Published in: Human gene therapy Vol. 21; no. 2; p. 143
• Main Authors: Tarantal, Alice F, Lee, C Chang I
• Format: Journal Article
• Language: English
• Published: United States 01.02.2010
• Subjects: Animals; Animals, Newborn - genetics; Animals, Newborn - metabolism; Dependovirus - genetics; Dependovirus - metabolism; Female; Fetal Therapies - methods; Fetus - metabolism; Gene Transfer Techniques; Genetic Therapy - methods; Genetic Vectors; Luciferases, Firefly - genetics; Luciferases, Firefly - metabolism; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Macaca mulatta - embryology; Macaca mulatta - genetics; Pregnancy; Transduction, Genetic; Transgenes - genetics
• ISSN: 1557-7422
• DOI: 10.1089/hum.2009.126

The safety and efficiency of fetal adeno-associated virus (AAV) gene delivery in rhesus monkeys and long-term monitoring of transgene expression by bioluminescence imaging (BLI) were evaluated. Early second-trimester fetal monkeys were administered AAV2/5, AAV2/9, or AAV2/10 vector supernatant preparations expressing firefly luciferase under the control of the cytomegalovirus promoter, using an intrathoracic (n = 6) or intramyocardial (n = 6) approach and established ultrasound-guided techniques. Postnatal BLI was performed monthly up to 6 months postnatal age (n = 12) and then every 3 months thereafter to monitor transgene expression up to 24 months postnatal age (27 months after gene transfer; n = 6). All AAV serotypes showed greater than 1.0 x 10(9) photons/sec at all time points evaluated with limited biodistribution to nontargeted anatomical sites. The highest levels of bioluminescence (photons per second) observed were noted with AAV2/9 and AAV2/10 when the three vector constructs were compared. To correlate in vivo findings at the tissue level, specimens were collected from selected animals and analyzed. Three-dimensional reconstruction showed that firefly luciferase expression was consistent with imaging and morphometric measures. These findings suggest that (1) high levels of AAV-mediated firefly luciferase expression can be found after fetal AAV gene transfer and without any evidence of adverse effects; (2) the intercostal muscles, myocardium, and muscular component of the diaphragm of developing fetuses are readily transduced with AAV2/5, AAV2/9, or AAV2/10; and (3) postnatal outcomes and long-term luciferase expression can be effectively monitored by BLI in young rhesus monkeys.