Genetica

Gene Therapy (2008) 15, 1311–1320
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ORIGINAL ARTICLE

Correction of the disease phenotype in the mouse
model of Stargardt disease by lentiviral gene therapy
J Kong1, S-R Kim1, K Binley2, I Pata1, K Doi1, J Mannik1, J Zernant-Rajang1, O Kan2, S Iqball2, S Naylor2,
JR Sparrow1,3, P Gouras1 and RAllikmets1,3
1

Department of Ophthalmology, Columbia University, New York, NY, USA; 2Oxford BioMedica (UK) Ltd, Oxford Science Park, Oxford,
UK and 3Department of Pathology and Cell Biology, Columbia University, New York, NY, USA

Autosomal recessive Stargardt disease (STGD1) is a macular
dystrophy caused by mutations in the ABCA4 (ABCR) gene.
The disease phenotype that is most recognizedin STGD1
patients, and also in the Abca4À/À mouse (a disease model),
is lipofuscin accumulation in retinal pigment epithelium. Here,
we tested whether delivery of the normal (wt) human ABCA4
gene to the subretinal space of the Abca4À/À mice via lentiviral
vectors would correct the disease phenotype; that is, reduce
accumulation of the lipofuscin pigment A2E. Equine infectious
anemia virus(EIAV)-derived lentiviral vectors were constructed expressing either the human ABCA4 gene or the
LacZ reporter gene under the control of the constitutive (CMV)
or photoreceptor-specific (Rho) promoters. Abca4À/À mice
were injected subretinally with 1 ml (B5.0 Â 105 TU) of each
EIAV vector in one eye at postnatal days 4 and 5. An injection
of saline, an EIAV-null vector, or an uninjectedcontralateral
eye served as a control. Mice were killed at various times
after injection to determine photoreceptor (PR) transduction

efficiency and A2E concentrations. EIAV-LacZ vectors transduced from 5 to 20% of the PRs in the injected area in mice.
Most importantly, a single subretinal injection of EIAV-CMVABCA4 to Abca4À/À mouse eyes substantially reduced
disease-associated A2E accumulationcompared to untreated
and mock-treated control eyes. Treated eyes of Abca4À/À
mice accumulated 8–12 pmol per eye (s.d. ¼ 2.7) of A2E 1
year after treatment, amounts comparable to wt controls,
whereas mock-treated or untreated eyes had 3–5 times more
A2E (27–39 pmol per eye, s.d. ¼ 1.5; P ¼ 0.001–0.005).
Although extrapolation to humans requires caution, the high
transduction efficiency of bothrod and cone photoreceptors
and the statistically significant reduction of A2E accumulation
in the mouse model of STGD1 suggest that lentiviral gene
therapy is a potentially efficient tool for treating ABCA4associated diseases.
Gene Therapy (2008) 15, 1311–1320; doi:10.1038/gt.2008.78;
published online 8 May 2008

Keywords: Stargardt disease; ABCA4; EIAV lentivirus; mouse model; A2EIntroduction
Autosomal recessive Stargardt disease (STGD1; MIM
248200) is arguably the most common hereditary
recessive macular dystrophy (estimated frequency of
1:8000–10 000 in the US).1 It is characterized by a highly
variable age of onset and clinical course. Most cases
present with juvenile to young-adult onset, insidious to
rapid central visual impairment, progressive bilateral
atrophy ofthe foveal retinal pigment epithelium (RPE)
and photoreceptors, and the frequent appearance of
yellow-orange flecks distributed around the macula
and/or the mid-retinal periphery.2,3
Several laboratories independently described ABCA4
(initially called ABCR) in 1997 as the causal gene for
arSTGD.4–6 Subsequently, several cases were reported
where ABCA4 mutations segregated with retinaldystrophies of significantly different phenotype, such as
Correspondence: Dr R Allikmets, Department of Ophthalmology,
Columbia University, Eye Institute Research, Room 715, 630 West
168th Street, New York, NY 10032, USA.
E-mail: rla22@columbia.edu
Received 16 October 2007; revised 6 March 2008; accepted 9 March
2008; published online 8 May 2008

autosomal recessive cone-rod dystrophy7,8 and...