Long-term
Outcome of gfp Gene Modified
Human RPE Xenografts into the Subretinal Space of Rabbits
WANG Feng, XU Ping, WU Ji-Hong, XIA Xin1,
SUN Hao-Long1, XU Xun1, HUANG Qian*
( Central Experimental Laboratory,Department of Ophthalmology, The First
People's Hospital of Shanghai,
Shanghai 200080, China )
AbstractThe possibility of delivery
genes to retina by using retinal pigment epithelium (RPE) transplantation was
investigated. Cultured human adult RPE cells were transfected with retrovirus
encoding green fluorescent protein (GFP), then GFP-expressing RPE cells were
transplanted into the subretinal space of rabbits through pars plana vitrectomy
under microscopy. The transplant sites were examined in vivo by
ophthalmoscope for fluorescence. The animals were euthanatized at 1, 2, 3, 4,
6, 10, 11, 14, 18, 20, 23, 24, 25, 33, 54 weeks, respectively, and the retinas
were studied histologically, including epi-fluorescent microscopy, confocal
microscopy and transmission electron microscopy. The GFP-expressing transplant
could be followed in the living retina up to 21 days by ophthalmoscope. The
epi-fluorescent microscopy examination disclosed survival of the transplanted
cells in 1 year with continual and significant GFP expression. It was observed
the transplanted hRPE-gfp cells were not only present at transplant
sites but spread over two to three quarters of retina. Generally, RPE
xenografts integrated individually into host RPE in a regular cobblestones
arrangement or formed a monolayer sheet between host RPE and neural retina. It
was observed that intravitreal injection of FK-506 weekly improved the survival
of RPE xenografts and reduced the infiltration of mononuclear microphages and
lymphocytes in choroids from 1 through 14 weeks after transplantation. The
results demonstrate a long-term survival of gene modified human RPE xenografts
into the subretinal space of rabbits and support the feasibility of this
approach for delivery genes to retina.
Key words retinal pigment epithelium/eye;
gene/transfer/modify; transplantation / xenotransplantation; green fluorescent
protein
*Corresponding author: Tel,
86-21-63240090-4601; Fax, 86-21-63240825； e-mail, [email protected]