Transplantation of cultured progenitor cells to the mammalian retina

Abstract

Multipotent progenitor cells have now been isolated from the brain and retina, expanded in culture, and transplanted to the central nervous system (CNS). Work in rodent models has shown that progenitor cells derived from the CNS readily engraft in the diseased retina of mature recipients, where they develop morphologies appropriate to the local microenvironment and express mature markers, including the photoreceptor protein rhodopsin. There is also evidence for graft-associated rescue of host photoreceptors and preservation of light sensitivity in the degenerating retina. Graft survival does not necessarily require immune suppression, as CNS progenitors can behave as an immunoprivileged cell type. The use of biodegradable polymers results in an organised implant and further improves graft survival. Efforts are underway at present to extend this work to the pig, with initial results showing engraftment in both the neural retina and retinal pigment epithelium (RPE).

Keywords::

• biodegradable polymers
• immune privilege
• neural stem cells
• regenerative medicine
• retinal degeneration
• tissue engineering

Acknowledgements

The author dedicates this work to the memory of Andrei Olenicoff. The author thanks all coauthors for their contributions to the work cited here, in particular M Young, who has been an inspiration to us all.