Research Fellows Directory
Dr Rachael Pearson
University College London
Retinal diseases lead to irreversible loss of the light-detecting cells of the eye, the photoreceptors. Replacement by cell transplantation represents a way of restoring vision but, until recently, has been largely unsuccessful. There are many potential sources of donor cells, including embryonic and adult stem cells. For photoreceptor transplantation to be successful, the donor cell must be transplanted into the eye, whereupon it must migrate into the recipient retina and then mature into a functional photoreceptor that correctly wires up to the next neurons in the visual pathway. Moreover, the recipient retina and higher visual areas must be able to correctly process the information from these new cells in order to restore vision, even in severely degenerate retinae. We have shown that photoreceptor transplantation is possible if the donor cells are at a critical developmental stage; they must be photoreceptor precursor cells, or immature photoreceptors, rather than cells at other stages of development. When transplanted into diseased eyes, these cells correctly integrate within a recipient retina, form new mature photoreceptors and restore vision in animal models of blindness. We have identified barriers within the diseased recipient retina that impede transplanted photoreceptor migration, and are determining ways of disrupting these barriers to permit increased integration. We are examining how the properties of the donor cell itself influence its ability to migrate and integrate with the aim of utilising these mechanism to enable more donor cells to integrate. As there is no ready source of photoreceptor precursors for clinical application, we have also developed protocols to generate appropriate, transplantable donor cells from stem cell populations.
Interests and expertise (Subject groups)