Development of photoreceptor-specific promoters and their utility to investigate EIAV lentiviral vector mediated gene transfer to photoreceptors.
BACKGROUND
We wanted to investigate the ability of recombinant equine infectious anemia virus (EIAV) vectors to transduce photoreceptor cells by developing a series of photoreceptor-specific promoters that drive strong gene expression in photoreceptor cells.


METHODS
Promoter fragments derived from the rhodopsin (RHO), the beta phosphodiesterase (PDE) and the retinitis pigmentosa (RP1) genes were cloned in combination with an enhancer element, derived from the interphotoreceptor retinoid-binding protein gene (IRBP), into luciferase reporter plasmids. An in vitro transient reporter assay was carried out in the human Y-79 retinoblastoma cell line. The optimal promoters from this screen were then cloned into the recombinant EIAV vector for evaluation in vivo following subretinal delivery into mice.


RESULTS
All promoters maintained a photoreceptor-specific expression profile in vitro and the gene expression was further enhanced in combination with the IRBP enhancer. The use of IRBP-combined RHO or PDE promoters showed modest but exclusive expression in photoreceptors following subretinal delivery to mice. By contrast an EIAV vector containing the cytomegalovirus (CMV) promoter drove reporter gene expression in both photoreceptors and retinal pigment epithelium.


CONCLUSIONS
It may be possible to use recombinant EIAV vectors containing photoreceptor-specific promoters to drive therapeutic gene expression to treat a range of retinal degenerative diseases where the photoreceptor cell is the primary disease target.
Nicoud
Marjorie
M
Oxford BioMedica (UK) Ltd., Medawar Centre, Robert Robinson Avenue, Oxford Science Park, Oxford OX4 4GA, UK.
Kong
Jian
J
Iqball
Sharifah
S
Kan
On
O
Naylor
Stuart
S
Gouras
Peter
P
Allikmets
Rando
R
Binley
Katie
K
D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D017931:DNA Primers; D004742:Enhancer Elements, Genetic; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D004860:Infectious Anemia Virus, Equine / Q000235:genetics*; D051379:Mice; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012160:Retina / Q000378:metabolism
D017931:DNA Primers