Antigen CD34+ marrow cells engraft lethally irradiated baboons.
The CD34 antigen is present on 1-4% of human marrow cells including virtually all hematopoietic progenitors detected by in vitro assays. Since the anti-CD34 monoclonal antibody 12-8 reacts with a similar marrow population in baboons, it was possible to test whether this antigen is expressed by stem cells responsible for hematopoietic reconstitution in vivo. CD34+ cells were enriched from marrows of five baboons using avidin-biotin immunoadsorption. After lethal irradiation, the five animals were given 15-27 X 10(6) autologous marrow cells (3.2-4.4 X 10(6) cells/kg) containing 65-91% CD34+ cells. All animals achieved granulocyte counts greater than 1,000/mm3 and platelet counts greater than 20 X 10(3)/mm3 by 13-24 d posttransplant and subsequently developed normal peripheral blood counts. Two additional animals received 184 and 285 X 10(6) marrow cells/kg depleted of CD34+ cells. One animal died at day 29 without engraftment, while the other had pancytopenia for greater than 100 d posttransplant. The data suggest that stem cells responsible for hematopoietic reconstitution are CD34+.
D000818:Animals; D000943:Antigens, Differentiation; D001853:Bone Marrow / Q000473:pathology; D016026:Bone Marrow Transplantation; D002469:Cell Separation; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000145:classification / Q000473:pathology; D010215:Papio; D010641:Phenotype; D011183:Postoperative Complications / Q000473:pathology; D011828:Radiation Chimera; D013577:Syndrome
D000943:Antigens, Differentiation