title: Gene Delivery by Subconjunctival Injection of Adenovirus in Rats: A Study of Local Distribution, Transgene Duration and Safety.
abstract: Subconjunctival injection is a minimally invasive route for gene delivery to ocular tissues, but has traditionally been limited to use in the cornea. The accurate ocular distribution of virus has not, however, been previously investigated. Adenovirus is an attractive gene vector as it can deliver large genes and allow for short-term gene expression, but how safe it is when delivered via subconjunctival injection remains to be established. We have characterized the bio-distribution and safety of subconjunctivally administered adenovirus in Brown Norway rats. The bio-distribution and transgene duration of adenovirus carrying luciferase gene (Ad-Luci) at various time intervals were evaluated via bioluminescence imaging after subconjunctival injection. Adenovirus carrying a reporter gene, β-galactosidase (Ad-LacZ) or hrGFP (Ad-hrGFP) was administered subconjunctivally and the viral distribution in various ocular tissues was assessed by histological analysis and quantitative PCR (qPCR). Hepatic damage was assessed by biochemical and immunohistological analysis with TUNEL stain. Systemic immunogenicity was assessed by measuring serum level of TNF-α via ELISA, 2 hours and 14 days after administration of adenovirus. Retinal function was examined by electroretinography. Subconjunctival injection of Ad-Luci induced luciferase expression in the injected eyes within 24 hours, for at least 64 days. Histological analysis showed adenovirus distributed across anterior and posterior ocular tissues. qPCR demonstrated different amounts of adenovirus in different ocular tissues, with the highest amounts closest to the injection site Unlike the intravenous route, subconjunctivally delivered adenovirus did not elicit any detectable hepatic injury or systemic immunogenicity. Retinal function was unaffected by adenovirus irrespective of administration route. In conclusion, an adenoviral vector administered subconjunctivally can infiltrate into different ocular tissues and lead to short-term ocular transgene expression, without causing hepatic injury and immune activation. Therefore, subconjunctivally administered adenovirus may be a promising gene delivery approach for managing anterior and posterior segment eye diseases requiring short-term therapy.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.|Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia.
authors.forename: Guei-Sheung
authors.initials: GS
authors.lastname: Liu
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.|Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia.
authors.forename: Jiang-Hui
authors.initials: JH
authors.lastname: Wang
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.
authors.forename: Jia Hui
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors.forename: Pei-Jhen
authors.initials: PJ
authors.lastname: Tsai
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Han-En
authors.initials: HE
authors.lastname: Tsai
authors.affiliation: Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Shwu-Jiuan
authors.initials: SJ
authors.lastname: Sheu
authors.affiliation: Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors.forename: Hsiu-Chen
authors.initials: HC
authors.lastname: Lin
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.|Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dusting
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Tai
authors.affiliation: Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.|National Defense Medical Center, Taipei, Taiwan.|Yuh-Ing Junior College of Health Care & Management, Kaohsiung, Taiwan.
authors.forename: Youn-Shen
authors.initials: YS
authors.lastname: Bee
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D003228:Conjunctiva; D018014:Gene Transfer Techniques / Q000009:adverse effects; D005822:Genetic Vectors; D008297:Male; D051381:Rats; D019076:Transgenes