An optimized protocol for efficient derivation of pancreatic islets from multiple human pluripotent stem cell lines

Future success of cell therapy for type 1 diabetes (T1D) relies on robust protocols for the differentiation of stem cells to pancreatic islets. However, currently established protocols generate stem cell-derived pancreatic islets (SC-islets) which contain non-endocrine cell populations and have immature functionality. Herein we report the development of a new protocol for the generation of potent SC-islets enriched in functional endocrine cells from multiple human pluripotent stem cell (hPSC) lines. We show that laminin-521 efficiently supports monolayer differentiation of 8 testes hPSC lines to endocrine progenitor (EP) stage. The efficiency was further improved by reducing the pancreatic progenitor (PP) stage. Importantly, we find that aggregation of EP reduces unwanted non-endocrine and proliferative cells. Subsequent suspension cultures generate SC-islets with strong in vitro glucose responsiveness, similar to human islets. Upon transplantation of 300 SC-islets into the anterior chamber of the eye of a diabetic mouse model, the SC-islets undergo further maturation in vivo and re-establish normal glycemic control. The SC-islets before and after transplantation are to a major extent free of non-endocrine cell populations. In conclusion, our robust differentiation protocol results in endocrine enriched and highly functional SC-islets that should be well suited for transplantation into patients with T1D.