Method of pre-inducing a state of immune tolerance before organ transplantation
Methods and compositions are described for the treatment of type I insulin-dependent diabetes mellitus and other conditions using newly identified stem cells that are capable of differentiation into a variety of pancreatic islet cells, including insulin-producing beta cells, as well as hepatocytes. Nestin has been identified as a molecular marker for pancreatic stem cells, while cytokeratin-19 serves as a marker for a distinct class of islet ductal cells. Methods are described whereby nestin-positive stem cells can be isolated from pancreatic islets and cultured to obtain further stem cells or pseudo-islet like structures. Methods for ex vivo differentiation of the pancreatic stem cells are disclosed. Methods are described whereby pancreatic stem cells can be isolated, expanded, and transplanted into a patient in need thereof, either allogeneically, isogeneically or xenogenically, to provide replacement for lost or damaged insulin-secreting cells or other cells.
1. A method of transplanting an organ in a mammal without the administration of immunosuppressive drugs, comprising the steps of:
(a) isolating nestin-positive pancreatic stem cells from a pancreatic islet of a mammalian donor;
(b) transplanting said nestin-positive pancreatic stem cells into a mammalian transplant recipient, wherein said transplanting induces a state of immune tolerance in the recipient toward the donor's stem cells; and
(c) transplanting an organ from said donor to said recipient, wherein said organ is trasplanted without the administration of immunosuppressive drugs.
2. A method of pre-inducing a state of immune tolerance prior to organ transplantation, comprising the steps of:
(a) isolating nestin-positive pancreatic stem cells from a pancreatic islet of a mammalian donor; and
(b) transplanting said nestin-positive pancreatic stem cells into a mammalian transplant recepient, wherein said transplanting induces a state of immune tolerance in the recipient toward the donor's stem cells prior to organ transplantation.