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Abstract #14268 Published in IGR 8-3
Mechanisms of AAV transduction in glaucoma-associated human trabecular meshwork cells
Borras T; Xue W; Choi VW; Bartlett JS; Li G; Samulski RJ; Chisolm SSJournal of Gene Medicine 2006; 8: 589-602
See also comment(s) by Curtis Brandt •
BACKGROUND: Glaucoma is a chronic eye disease which leads to irreversible blindness. The trabecular meshwork tissue controls intraocular pressure (IOP), which is the major risk factor for glaucoma. Gene therapy treatment of chronic diseases requires the use of long-term expression, low toxicity and lack of immune response vectors. Adeno-associated viruses (AAV) possess these characteristics but have been unable to transduce the trabecular meshwork. Because of the importance of regulating elevated IOP by long-term gene therapy, we investigated mechanisms of AAV transduction to the human trabecular meshwork (TM). METHODS: Primary human trabecular meshwork cells (HTM) a nd perfused organ cultures were infected with rAAV2-GFP, RGD-pseudotyped rAAV2-GFP alone, or combined with recombinant ΔE1/E3 adenoviruses. Intracellular rAAV2 DNA and RNA were measured by relative quantitative and real-time TaqMan polymerase chain reaction (PCR). Host transcriptome was analyzed using high-density oligonucleotide microarrays. One transduction mechanism was tested using self-complementary AAV (scAAV). RESULTS: The dramatic transduction enhancement obtained upon co-infection of rAAV2 with ΔE1/E3 adenoviruses provides insights into transduction mechanisms in the HTM. Even if not transduced, rAAV2 enters TM cells. GeneChip analysis showed significant changes in host genes involved in cell cycle and DNA replication. Consequently, scAAV-GFP transduction was highly efficient. Other transduction-enhancement genes included coxsackie adenovirus receptor (CAR) and genes relevant to trabecular meshwork function. CONCLUSIONS: The rate-limiting step of AA V transduction was not viral entry failure but, at least in part, host downregulation of DNA replication. Additional specific host genes might be involved. Our study revealed genes and mechanisms which led for the first time to efficient AAV transduction of the HTM.
Dr. T. Borras, Department of Ophthalmology, University of North Carolina School of Medicine, 103 Mason Farm Road, Chapel Hill, NC 27599-7041, USA
Classification:
11 Medical treatment
2.5.1 Trabecular meshwork (Part of: 2 Anatomical structures in glaucoma > 2.5 Meshwork)
