[HTML][HTML] Transplantation of photoreceptors into the degenerative retina: Current state and future perspectives

SJ Gasparini, S Llonch, O Borsch, M Ader - Progress in Retinal and Eye …, 2019 - Elsevier
SJ Gasparini, S Llonch, O Borsch, M Ader
Progress in Retinal and Eye Research, 2019Elsevier
The mammalian retina displays no intrinsic regenerative capacities, therefore retinal
degenerative diseases such as age-related macular degeneration (AMD) or retinitis
pigmentosa (RP) result in a permanent loss of the light-sensing photoreceptor cells. The
degeneration of photoreceptors leads to vision impairment and, in later stages, complete
blindness. Several therapeutic strategies have been developed to slow down or prevent
further retinal degeneration, however a definitive cure ie replacement of the lost …
Abstract
The mammalian retina displays no intrinsic regenerative capacities, therefore retinal degenerative diseases such as age-related macular degeneration (AMD) or retinitis pigmentosa (RP) result in a permanent loss of the light-sensing photoreceptor cells. The degeneration of photoreceptors leads to vision impairment and, in later stages, complete blindness. Several therapeutic strategies have been developed to slow down or prevent further retinal degeneration, however a definitive cure i.e. replacement of the lost photoreceptors, has not yet been established. Cell-based treatment approaches, by means of photoreceptor transplantation, have been studied in pre-clinical animal models over the last three decades. The introduction of pluripotent stem cell-derived retinal organoids represents, in principle, an unlimited source for the generation of transplantable human photoreceptors. However, safety, immunological and reproducibility-related issues regarding the use of such cells still need to be solved. Moreover, the recent finding of cytoplasmic material transfer between donor and host photoreceptors demands reinterpretation of several former transplantation studies. At the same time, material transfer between healthy donor and dysfunctional patient photoreceptors also offers a potential alternative strategy for therapeutic intervention. In this review we discuss the history and current state of photoreceptor transplantation, the techniques used to assess rescue of visual function, the prerequisites for effective transplantation as well as the main roadblocks, including safety and immune response to the graft, that need to be overcome for successful clinical translation of photoreceptor transplantation approaches.
Elsevier