Human embryonic stem cell-derived retinal pigment epithelial cells functionally integrate and rescue photoreceptors in a large-eyed model of geographic atrophy

Abstract

Purpose : Human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells could replace lost tissue in geographic atrophy (GA) but efficacy has yet to be demonstrated in a large-eyed model. Here we describe a xeno-free and defined differentiation method for hESC-RPE and explore their integration and function in a large-eyed model of GA.

Methods : Xeno-free and defined derivation of hESC-RPE cultures was explored using different Bruch's membrane-associated laminin matrices. Derived cells were analyzed for purity, surface marker-expression, polarity and function using flow cytometry, immunohistochemistry, and assays for directed growth factor secretion, transepithelial resistance, and phagocytosis respectively. Suspensions of differentiated cells were transplanted subretinally into a novel rabbit model of GA and cell fate and in vivo function was analyzed by immunohistochemistry and real-time high-resolution imaging.

Results : Highly homogeneous populations of mature, polarized and functional hESC-RPE were obtained on all laminins tested with the highest yield observed using human recombinant laminin-521. Subretinal transplants of laminin-521-derived hESC-RPE in suspension integrated as polarized monolayers that exhibited phagocytic and photoreceptor rescue capacity for up to 8 months.

Conclusions : Altogether, we have developed a xeno-free and defined hESC-RPE differentiation method and present the first evidence of functional integration of clinically compliant hESC-RPE in a large-eyed GA model.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.