Human hematopoietic precursors in long-term culture: single CD34+ cells that lack detectable T cell, B cell, and myeloid cell antigens produce multiple colony-forming cells when cultured with marrow stromal cells.
CD34+ human marrow cells not expressing T cell-, B cell-, and myeloid cell-associated antigens (TBM-) were cloned by two-color cell sorting into culture wells containing irradiated marrow stromal cells. After 4 wk of culture, 3.7 +/- 2.1% of these cells generated colony-forming cells (CFC), with each of these cells generating 6.3 +/- 5.3 CFC. This was not due to the 0.5 +/- 0.5% CFC present in the purified CD34+ TBM- cells, as less than 1% of CFC persist in these cultures. This is the first demonstration that single immature precursor cells in human long-term cultures generate multiple CFC progeny. The immature nature of these clonable CD34+ TBM- precursors suggests their candidate status as human hematopoietic stem cells.
Pediatric Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
R G
RG
Andrews
J W
JW
Singer
I D
ID
Bernstein
D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D000943:Antigens, Differentiation / Q000096:biosynthesis*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans
D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte