A new model of retinal pigment epithelium transplantation with microspheres.
OBJECTIVE
To develop a 3-dimensional carrier system for subretinal transplantation of human fetal retinal pigment epithelial (HFRPE) cells and to assess their growth pattern in the rabbit subretinal space.


METHODS
After a standard 3-port vitrectomy, HFRPE cells grown as microspheres on cross-linked fibrinogen were introduced into the subretinal space of rabbits. The eyes were studied at 7, 14, and 30 days after surgery by ophthalmoscopy and light microscopy.


RESULTS
Ophthalmoscopically, at day 7, 11 (61%) of the 18 eyes showed radiating hyperpigmentation around the transplanted HFRPE microspheres. The results of a histological examination revealed a monolayer outgrowth of HFRPE cells, overlying host retinal pigment epithelium. The control eyes revealed a patch of chorioretinal atrophy with lymphocytic infiltration around the microspheres.


CONCLUSIONS
Human fetal retinal pigment epithelial cells grown as microspheres on cross-linked fibrinogen can be successfully transplanted into the subretinal space. Cells can survive for at least 1 month and form a monolayer over the host retinal pigment epithelium cells, with a mild local inflammatory response. The difference in inflammatory responses between the eyes that underwent transplantation and the control eyes may suggest a modulating effect of the HFRPE cells on inflammation, immunity, or both. This new xenogenic model may have importance in the study of subretinal transplant cell biology and the associated immune response.


CONCLUSIONS
The results of this study may be important for better understanding of the mechanisms of retinal pigment epithelium cell behavior after transplantation. The proposed model may be applicable for future clinical and experimental investigations in the area of retinal pigment epithelium transplantation.
Oganesian
A
A
Department of Ophthalmology and Visual Science Center, The University of Chicago, Ill 60637, USA. aoganesi@midway.uchicago.edu
Gabrielian
K
K
Ernest
J T
JT
Patel
S C
SC
D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D017690:Cell Transplantation / Q000379:methods; D002478:Cells, Cultured; D005123:Eye / Q000196:embryology; D016332:Fetal Tissue Transplantation; D019084:Fluorescent Antibody Technique, Indirect; D005654:Fundus Oculi; D006680:HLA Antigens / Q000032:analysis; D006801:Humans; D007633:Keratins / Q000032:analysis; D008954:Models, Biological; D009887:Ophthalmoscopy; D010857:Pigment Epithelium of Eye / Q000737:chemistry / Q000473:pathology / Q000637:transplantation*; D011817:Rabbits; D012160:Retina / Q000737:chemistry / Q000473:pathology / Q000601:surgery*; D018874:Spheroids, Cellular / Q000737:chemistry / Q000473:pathology / Q000637:transplantation*; D014821:Vitrectomy
D015703:Antigens, CD; D006680:HLA Antigens; D007633:Keratins