title: Human bone marrow CD34- cells engraft in vivo and undergo multilineage expression that includes giving rise to CD34+ cells.
abstract: We used the human/sheep competitive engraft model to investigate the in vivo engraftment potential of human CD34-, Lin- cells. In three separate studies, transplantation of CD34+, Lin- and CD34-, Lin- cells from the same normal human donors into preimmune fetal sheep resulted in long-term engraftment and multilineage hematopoietic cell/progenitor expression. Human cell/progenitor activities of the CD34+ group were CD3, 0.52%; CD13, 0.36%; CD45, 1.02%; glyA, 1.78%; HLA-DR, 0.99%; colony-forming units (CFU)-Mix, 7.1%; and granulocyte-macrophage CFU (CFU-GM), 13.7%; those of the CD34- group were CD3, 0.24%; CD45, 2.49%; glyA, 0.75%; HLA-DR, 0.3%; CFU-Mix, 7.1%; and CFU-GM, 4.3%. Of special interest was the detection of highly significant numbers (1 x 10[9] cells) of human CD34+ cells in animals transplanted with CD34- cells. Secondary transplantation and limiting dilution studies confirmed the presence of cells with long-term engraftment potential in CD34- populations. The results presented here demonstrate that the CD34- fraction of normal human bone marrow contains cells capable of engraftment and differentiation into CD34+ progenitors and multiple lymphohematopoietic lineages in primary and secondary hosts.
authors.affiliation: Department of Veterans Affairs Medical Center, University of Nevada, Reno 89520, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Zanjani
authors.forename: G
authors.initials: G
authors.lastname: Almeida-Porada
authors.forename: A G
authors.initials: AG
authors.lastname: Livingston
authors.forename: A W
authors.initials: AW
authors.lastname: Flake
authors.forename: M
authors.initials: M
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D000818:Animals; D018952:Antigens, CD34 / Q000032:analysis*; D001854:Bone Marrow Cells / Q000166:cytology* / Q000276:immunology; D016026:Bone Marrow Transplantation; D002454:Cell Differentiation; D003114:Colony-Forming Units Assay; D005333:Fetus; D006098:Granulocytes / Q000166:cytology; D006801:Humans; D016130:Immunophenotyping; D012756:Sheep / Q000196:embryology; D018183:Transplantation Chimera; D014183:Transplantation, Heterologous
chemical_list: D018952:Antigens, CD34