Engraftment and long-term expression of human fetal hemopoietic stem cells in sheep following transplantation in utero.

Abstract

Hemopoietic stem cells from human fetal liver were transplanted in utero into preimmune fetal sheep (48-54 days of gestation). The fate ofdonor cells was followed using karyotype analysis, by immunofluorescence labelingwith anti-CD antibodies, and by fluorescent in situ hybridization using human-specific DNA probes. Engrftment occurred in 13 of 33 recipients. Of five live born sheep that exhibited chimerism, all expressed human cells in the marrow, whereas three expressed them in blood as well.Engraftment was multilineage (erythroid, myeloid, and lymphoid) and human hemopoietic progenitors (multipotent colony-forming units, colony-forming units-granulocyte, macrophage, and erythroid burst-forming units) capable of forming colonies in vitro were detected in all five lambs for > 2 yr. These progenitors responded to human-specific growth-factors both in vitro and in vivo. Thus the administration of recombinanthumanIL-3andgranulocytemacrophage-colony-stimulating factor to chimeric sheep resulted in a 2.1-3.4-fold increase in the relative expression of donor (human) cells. These results demonstrate that the permissive environment ofthe preimmune fetal sheep provides suitable conditions for the engraftment and long-term multilineage expression of human hemopoietic stem cells in a large animal model. In this model, donor human cells appear to retain certain phenotypic and functional characteristics that can be used to manipulate the size of donor cell pool.

Multiorgan engraftment and differentiation of human cord blood CD34 + Lin − cells in goats assessed by gene expression profiling

“…Thus, the need for immunosuppression and myeloablation used for postnatal transplantation can be avoided. Allogeneic and xenogeneic chimerism has been generated by in utero transplantation procedures, and fetal engraftment of allogeneic and xenogeneic HSC has been tested in mouse, sheep, and monkey and more recently in pigs and goats (8)(9)(10)(11)(12). Questions remain regarding the engraftment, homing, and differentiation of allogeneic or xenogeneic HSC, as well as the gene expression of the engrafted cells in different tissues of the recipients.…”

Natural killer cell depletion by anti-asialo GM1 antiserum treatment enhances human hematopoietic stem cell engraftment in NOD/Shi-scid mice

“…In sheep and dog models, intrauterine injection of human HSC has reproducibly resulted in long-term reconstitution of human hematopoiesis. 3,4 Genetically immuno-deficient mice homozygous for the scid mutation lacking functional B and T cells are widely used for xenogeneic transplantation of human HSC. 5,6 More recently, to develop a mouse stock with defective lymphoid function accompanied by reduced nonadaptive immunologic function, the scid mutation was backcrossed on to the nonobese diabetic (NOD/Lt) mouse background.…”

Transplantation of a fetus with paternal Thy-1+CD34+cells for chronic granulomatous disease

“…25,26,28,29 It appears that significant chimerism is achieved only when the donor HSCs or their progeny have a competitive advantage over the host cells. 30 Allogeneic and xenogeneic IUT in large animals has had mixed results with some studies achieving clinically significant levels of chimerism [31][32][33][34][35][36] whereas others have failed to engraft donor cells above 1%. 37,38 An explanation for the disparate results in the various animal models is not apparent.…”