Grafting of ARPE-19 and Schwann cells to the subretinal space in RCS rats.
OBJECTIVE
To study the distribution of the human retinal pigment epithelium (hRPE) cell line ARPE-19 and human Schwann (hSC) cells grafted to the subretinal space of the Royal College of Surgeon (RCS) rat and the relation of graft cell distribution to photoreceptor rescue.


METHODS
Cell suspensions of both donor types were injected into the subretinal space of 3-week-old dystrophic RCS rats through a transscleral approach, human fibroblast and medium were used as control grafts. All animals were maintained on oral cyclosporine. At 1, 2, 4, 6, 15, 28, and 36 weeks after grafting, animals were killed. Human cell-specific markers were used to localize donor cells.


RESULTS
Both donor cell types, as revealed by antibodies survived for a substantial time. Their distribution was very different: hRPE cells formed a large clump early on and, with time, spread along the host RPE in a layer one to two cells deep, whereas hSCs formed many smaller clumps, mainly in the subretinal space. Both cells rescued photoreceptors beyond the area of donor cell distribution. The number of surviving cells declined with time.


CONCLUSIONS
Both hRPE and hSC grafts can survive and rescue photoreceptors for a substantial time after grafting. The number of both donor cell types declined with time, which could be an immune-related problem and/or due to other factors intrinsic to the host RCS retina. The fact that rescue occurred beyond the area of donor cell distribution suggests that diffusible factors are involved, raising the possibility that the two cell types function in a similar manner to rescue photoreceptors.
John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, Utah 84132, USA.
Shaomei
S
Wang
Bin
B
Lu
Patrick
P
Wood
Raymond D
RD
Lund
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002452:Cell Count; D002470:Cell Survival; D017690:Cell Transplantation; D002478:Cells, Cultured; D005110:Extracellular Space; D006801:Humans; D007124:Immunoenzyme Techniques; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D010857:Pigment Epithelium of Eye / Q000378:metabolism / Q000637:transplantation*; D051381:Rats; D011922:Rats, Mutant Strains; D012162:Retinal Degeneration / Q000601:surgery*; D012583:Schwann Cells / Q000378:metabolism / Q000637:transplantation*; D013997:Time Factors
D015415:Biomarkers