title: T lymphocyte differentiation in vitro from adult human prethymic CD34+ bone marrow cells.
abstract: Pluripotent lymphohematopoietic stem cells are probably confined to bone marrow cells expressing CD34 surface molecules. To investigate the capacity of adult human CD34+ bone marrow cells to differentiate along the T lymphoid lineage, we plated purified CD34+ cells from healthy adults in liquid culture on adherent thymic stromal cells prepared from HLA- or blood group-mismatched postnatal thymic tissue. We show that purified CD34+CD3-CD4-CD8- bone marrow cells contained progenitors with the ability to differentiate into CD4+ and CD8+ T lymphocytes expressing surface (s)CD3 and T cell receptor alpha/beta in vitro. These progenitors were found in the CD34+CD2+sCD3-CD4-CD8-, CD34+CD7+sCD3-CD4-CD8-, and CD34+CD2+CD7+sCD3-CD4-CD8-, as well as in the CD34+CD2-sCD3-CD4-CD8-, CD34+CD7-sCD3-CD4-CD8-, and CD34+CD2-CD7-sCD3-CD4-CD8- subsets, indicating that T lymphocyte progenitors sensitive to signals mediated by thymic stroma in vitro are not restricted to CD34+ cells already coexpressing early T lymphocyte-associated markers. Finally, we show that T lymphopoiesis was enhanced by c-kit ligand.
authors.affiliation: Institute of Transplantation Immunology, National Hospital, Oslo, Norway.
authors.forename: G E
authors.initials: GE
authors.lastname: Tjønnfjord
authors.forename: O P
authors.initials: OP
authors.lastname: Veiby
authors.forename: R
authors.initials: R
authors.lastname: Steen
authors.forename: T
authors.initials: T
authors.lastname: Egeland
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000032:analysis*; D018952:Antigens, CD34; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D015704:CD4 Antigens; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell