Abstract
Purpose :
Transplantation of retinal pigment epithelium (RPE) differentiated from human pluripotent stem cells (hPSC) is a potential treatment strategy for retinal degeneration. In addition to production of clinical-grade hPSC-RPE, the grafts may need to be safely shipped to multiple clinical centers. Here we evaluated the integrity of mature epithelial monolayers derived from xeno- and feeder-free produced human embryonic stem cell –derived RPE (hESC-RPE) prior and after intercontinental live shipment.
Methods :
Human hESC lines were maintained in a defined, xeno- and feeder-free culture system, and thereafter differentiated to RPE with our previously established method. The cells were matured for six to seven weeks on porous polyester membrane after which they were shipped in five separate shipments in a temperature controlled container from Finland to Singapore using a high glucose CO2-independent medium. The hESC-RPE cells were characterized before and after shipment by morphology, transepithelial electrical resistance (TER), immunostainings, phagocytosis activity and histology. After recovery time of few days, the cells were transplanted in non-human primates with compromised blood retinal barrier and analyzed four weeks post-transplantation.
Results :
After 33-54 hours in shipment, the hESC-RPE had equivalent characteristics in vitro as before shipment including TER (270 Ωcm2 vs. 250 Ωcm2), morphology and expression of proteins critical for RPE functionality including Na,K-ATPase, bestrophin, and MERTK. Preliminary evidence shows that when xenografted into non-human primates, hESC-RPE monolayers mostly survived, and were able to support retinal functions. However, in some regions disruption of the hESC-RPE monolayer was detected possibly due to immune reactions towards the xenograft.
Conclusions :
Our xeno- and feeder-free production generated high-quality cells for potential clinical use. The developed shipping protocol allowed intercontinental delivery of live cell grafts for RPE transplantation, thus showing centralized cell production in one unit and distribution of living cell product around globe is a viable option for cell therapy applications.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.