The invention discloses a substantially pure population of human
pancreatic progenitor cells and methods of isolating and culturing the
pancreatic progenitor cells. By carefully manipulating the
microenvironment of the pancreatic progenitor cells, multiple passages
are attainable wherein the pancreatic progenitor cells do not senesce and
furthermore, are capable of becoming functional exocrine or endocrine
cells. In addition, several methods of use of human pancreatic progenitor
cells are disclosed herein.