Isolation of non-hematopoietic stem cells from umbilical cord blood

Abstract

An intrinsically pluripotent, CD45 negative population from placental cord blood, termed unrestricted somatic stem cells (USSC) as a rare population grows adherently and can be expanded to large quantities of cells without losing pluripotency. Thus, in vitro USSC homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, hematopoietic and neural cells including astrocytes and neurons expressing neurofilament, sodium channel protein and various neurotransmitter phenotypes are demonstrated. Stereotactic implantation of USSC into intact adult rat brain revealed that human Tau-positive cells persisted for several months, showing migratory activity and a typical neuron-like morphology. In vivo differentiation of USSC along mesodermal and endodermal pathways was demonstrated in animal models. Bony reconstitution was observed after transplantation of USSC-loaded calcium phosphate cylinders in nude rat femurs. Chondrogenesis occurred after transplanting cell-loaded Gelfoam sponges into nude mice. Transplantation of USSC in a non-injury model, the preimmune fetal sheep, resulted in up to 5% human hematopoietic engraftment. More than 20% albumin-producing human parenchymal hepatic cells with absence of cell fusion as well as substantial numbers of human cardiomyocytes in both atria and ventricles of the sheep heart were detected still over one year following USSC transplantation. No malignant cell transformation was observed in any of these animals. An intrinsically pluripotent, CD45 negative population from placental cord blood, termed unrestricted somatic stem cells (USSC) as a rare population grows adherently and can be expanded to large quantities of cells without losing pluripotency. Thus, in vitro USSC homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, hematopoietic and neural cells including astrocytes and neurons expressing neurofilament, sodium channel protein and various neurotransmitter phenotypes are demonstrated. Stereotactic implantation of USSC into intact adult rat brain revealed that human Tau-positive cells persisted for several months, showing migratory activity and a typical neuron-like morphology. In vivo differentiation of USSC along mesodermal and endodermal pathways was demonstrated in animal models. Bony reconstitution was observed after transplantation of USSC-loaded calcium phosphate cylinders in nude rat femurs. Chondrogenesis occurred after transplanting cell-loaded Gelfoam sponges into nude mice. Transplantation of USSC in a non-injury model, the preimmune fetal sheep, resulted in up to 5% human hematopoietic engraftment. More than 20% albumin-producing human parenchymal hepatic cells with absence of cell fusion as well as substantial numbers of human cardiomyocytes in both atria and ventricles of the sheep heart were detected still over one year following USSC transplantation. No malignant cell transformation was observed in any of these animals.