Abstract

SO.08.08

Stem cells and progenitor cells: candidate cell types for the development of cell-based therapies for retinal disorders

Bartsch U.
Klinik und Poliklinik für Augenheilkunde, Transplantationslabor, Universitätsklinikum Hamburg-Eppendorf, Hamburg

Objective: Stem cells are undifferentiated multipotent cells with the ability to self-renew. Stem cells are also amenable to genetic manipulations. They are thus candidate cells to develop ex vivo gene therapies and cell replacement strategies. We have developed methods to genetically modify neural stem cells (NSCs) with the final aim to use these cells to target therapeutic gene products to the diseased retina. Furthermore, we have performed transplantation experiments with primary retinal cells to study whether grafted cells are capable to integrate into the adult retina and to differentiate into retinal cell types.
Methods: NSCs were either transfected with multigenic expression vectors or transduced with bicistronic lentiviral vectors. Both expression systems allow the simultaneous expression of a gene of interest and a reporter gene. Primary retinal cell suspensions were prepared from young EGFP-transgenic mice, and grafted into the subretinal space of adult wild-type mice. Donor cells were analyzed by immunohistochemistry and electron microscopy.
Results: Genetically modified NSCs were selected by their expression of the reporter genes. Selected cells were again expanded or cloned, giving rise to cultures with homogenous expression levels of the transgenes. A fraction of the subretinally grafted primary retinal cells integrated into the outer nuclear layer. Here, they differentiated into cells displaying the typical morphology and antigen profile of rod photoreceptor cells.
Conclusions: Intraretinally grafted NSCs integrate into the normal and diseased retina where they survive for extended periods of time. Transplantations of genetically engineered NSCs might thus be a strategy to target therapeutic gene products to the diseased retina. The integration of subretinally grafted primary retinal cells into the outer nuclear layer, and the differentiation of donor cells into rod photoreceptors indicate that cell transplantation might be a feasible approach to replace dysfunctional or degenerated retinal cell types.
Supported by the Bundesministerium für Bildung und Forschung and the Ernst und Claere Jung Stiftung

Copyright: Porstmann Kongresse GmbH. All rights reserved. Impressum, Disclaimer.