title: A developing picture of lymphopoiesis in bone marrow.
abstract: The earliest progenitors of lymphocytes are extremely rare and typically present among very complex populations of hematopoietic cells. Additionally, it is difficult to know how cells with any given set of characteristics are developmentally related to stem cells and maturing lymphoid precursors. However, it is now possible to divide bone marrow into progressively smaller fractions and exploit well-defined culture systems to determine which ones contain cells that can turn into lymphocytes. Analysis of steroid hormone sensitive cells and use of two-step cultures is providing additional information about the most likely differentiation pathways for B and natural killer cell lineage lymphocytes. A newly identified category of early lymphoid progenitors can now be sorted to high purity from RAG1/GFP knock in mice. Furthermore, the same experimental model makes it possible to image lymphoid progenitors in fetal and adult hematopoietic tissues.
authors.affiliation: Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Hirose
authors.forename: Taku
authors.initials: T
authors.lastname: Kouro
authors.forename: Hideya
authors.initials: H
authors.lastname: Igarashi
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yokota
authors.forename: Nobuo
authors.initials: N
authors.lastname: Sakaguchi
authors.forename: Paul W
authors.initials: PW
authors.lastname: Kincade
mesh_terms: D000818:Animals; D018941:Antigens, CD19 / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D001853:Bone Marrow / Q000033:anatomy & histology; D001854:Bone Marrow Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D029721:Drosophila Proteins; D049452:Green Fluorescent Proteins; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D038041:Lymphopoiesis / Q000276:immunology / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D018448:Models, Immunological; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
chemical_list: D018941:Antigens, CD19; D002352:Carrier Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D008164:Luminescent Proteins; C410902:lin protein, Drosophila; C064658:RAG-1 protein; D049452:Green Fluorescent Proteins; D019009:Proto-Oncogene Proteins c-kit; D017493:Leukocyte Common Antigens