Cells with surface expression of CD133highCD71low are enriched for tripotent colony-forming progenitor cells in the adult murine pancreas.

Progenitor cells in the adult pancreas are potential sources of endocrine beta cells for treating type 1 diabetes. Previously, we identified tri-potent progenitor cells in the adult (2–4 month-old) murine pancreas that were capable of self-renewal and differentiation into duct, acinar, and endocrine cells in vitro. These progenitor cells were named pancreatic colony-forming units (PCFUs). However, because PCFUs are a minor population in the pancreas (~ 1%) they are difficult to study. To enrich PCFUs, strategies using cell-surface marker analyses and fluorescence-activated cell sorting were developed. We found that CD133^(high)CD71^(low) cells, but not other cell populations, enriched PCFUs by up to 30 fold compared to the unsorted cells. CD133^(high)CD71^(low) cells generated primary, secondary, and subsequent colonies when serially re-plated in Matrigel-containing cultures, suggesting self-renewal abilities. In the presence of a laminin hydrogel, CD133^(high)CD71^(low) cells gave rise to colonies that contained duct, acinar, and Insulin+ Glucagon+ double-hormonal endocrine cells. Colonies from the laminin hydrogel culture were implanted into diabetic mice, and five weeks later duct, acinar, and Insulin+ Glucagon− cells were detected in the grafts, demonstrating tri-lineage differentiation potential of CD133^(high)CD71^(low) cells. These CD133^(high)CD71^(low) cells will enable future studies of putative adult pancreas stem cells in vivo.