Isolation of a candidate human hematopoietic stem-cell population.
We have identified a rare (0.05-0.1%) subset of human fetal bone marrow cells that contains multipotent hematopoietic precursors. The population of human precursor cells that express Thy-1 and CD34 but no known lineage markers is enriched for clonogenic activity that establishes long-term, multilineage (myelomonocytic and B lymphoid) cultures on mouse marrow stromal lines. Further, the Thy-1+CD34+ subset that takes up little of the fluorescent mitochondrial dye rhodamine 123 contains virtually all the cells that establish long-term cultures. In human fetal thymus transplanted into SCID (severe combined immunodeficiency) mice, Thy-1+CD34+ fetal bone marrow cells differentiate into T lymphocytes. In two of nine cases, allogeneic Thy-1+CD34+ cells could engraft intact human fetal bone marrow grown in SCID mice, resulting in donor-derived myeloid and B cells. By extrapolation, the rare human Thy-1+Lin-CD34+ cell population contains pluripotent hematopoietic progenitors; we propose that it is highly enriched for candidate hematopoietic stem cells.
SyStemix Inc., Palo Alto, CA 94303.
C M
CM
Baum
I L
IL
Weissman
A S
AS
Tsukamoto
A M
AM
Buckle
B
B
Peault
D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34; D000954:Antigens, Surface / Q000032:analysis; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D005434:Flow Cytometry; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000166:cytology; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D016513:Mice, SCID; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000166:cytology
D015703:Antigens, CD; D018952:Antigens, CD34; D000954:Antigens, Surface; D008562:Membrane Glycoproteins; D018800:Thy-1 Antigens