UCSF

Cell replacement therapy using β cells derived from stem cells is a promising alternative to conventional diabetes treatment options. Although current differentiation methods produce glucose-responsive β cells, they can also yield populations of undesired endocrine progenitors and other proliferating cell types that might interfere with long-term islet function and safety of transplanted cells. Here, we describe the generation of an array of monoclonal antibodies against cell surface markers that selectively label stem cell-derived islet cells. A high-throughput screen identified promising candidates, including three clones that mark a high proportion of endocrine cells in differentiated cultures. A scalable magnetic sorting method was developed to enrich for human pluripotent stem cell (hPSC)-derived islet cells using these three antibodies, leading to the formation of islet-like clusters with improved glucose-stimulated insulin secretion and reduced growth upon transplantation. This strategy should facilitate large-scale production of functional islet clusters from stem cells for disease modeling and cell replacement therapy.