Abstract
Purpose :
Age-related macular degeneration and inherited retinal degenerations represent the leading causes of untreatable blindness in the developed world. Cell replacement therapy is one therapeutic strategy for the treatment of patients with photoreceptor loss. An essential requirement for cell-based therapies is the establishment of robust manufacture process that allow the derivation of large quantities of highly pure transplantable cells from renewable sources. Photoreceptors precursor cells (PRPCs) generated from human pluripotent stem cells (hPSCs) are potential cell sources for photoreceptor replacement therapy.
Methods :
Human iPS cells reprogrammed from fibroblasts with RNA were used in the current study. Human iPS cells were transitioned from conventional 2D monolayer to 3D sphere culture in disposable spinner flasks. Retinal neuron differentiation was initiated with the supplement of small molecules and continued with 3D-sphere dissociation/reformation for up to 100 days. Retinal neuron identities at different developmental stages were analyzed and confirmed by immunocytochemistry, flow cytometry and real-time PCR.
Results :
Our well controlled 3D sphere differentiation system sequentially generated early (Rax1+) and late (Chx10+) committed retinal neuron progenitors (CRNPs), PRPCs (NR2E3+/NRL+) and photoreceptor-like cells (REC+/RHOD+) with high purity. Starting with 3 x 106 human iPS cells we routinely generated 3-4.5 x 109 PRPCs with a purity of approximately 95% from multiple iPS cell lines. Human iPS cell-derived early and late CRNPs, PRPCs and photoreceptor-like cells can be cryo-preserved for more than 2 years.
Conclusions :
Our novel 3D sphere platform is amenable to the development of a GMP-compliant retinal cell manufacturing protocol from multiple renewable hPSC sources for future preclinical studies and human cell replacement therapies.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.