gms | German Medical Science

Purpose: Transplanted autologous pigment cells in suspension are well tolerated for several years in the subretinal space of AMD patients, however no significant improvement in vision is achieved. We postulate that vision improvement will require (a) that the transplanted cells be in a monolayer and (b) that the cells are genetically modified to express factors to maintain self and neural cell health and inhibit choroidal blood vessel growth. Since transfection of cells to be transplanted using viral vectors is complicated by the possible dissemination of the virus as well as severe immune reaction, we have explored transfection of pigment epithelium-derived factor (PEDF) in pigment cells using non-viral protocols.

Methods: Three recombinant plasmids p-N-PEDF-GFP, p-N-PEDF IV, and p-L-GFP-PEDF IV were transfected into human RPE cells by electroporation.

Results: Using electroporation RPE cells can be transfected in vitro with an efficiency of up to 80%. Sequencing of the different PEDF plasmids confirmed the in frame fusion of PEDF with EGFP or combined His- and Myc-Tag alone. Analysis of transfected RPE cells with the three different plasmids revealed that the PEDF fusion proteins were successfully expressed by transfected cells.

Conclusions: The genetic modification in vitro of pigment epithelial cells using non-viral transfection protocols could improve the potential therapeutic treatment of retinal degenerative diseases. Transplantation of pigment cells that carry genes expressing specific factors can modulate a particular cell function that requires to be enhanced or suppressed to treat and/or ameliorate a genetic-based or degenerative disorder. Supported by IZKF Biomat.