title: Untangling the T branch of the hematopoiesis tree.
abstract: T cells develop in the thymus. Previous work suggested an early separation of lymphoid from myeloerythroid lineages during hematopoiesis and hypothesized the thymus was settled exclusively by lymphoid-restricted hematopoietic progenitors. Recent data have instead established the existence of lymphoid-myeloid progenitors, which possess lymphoid and myeloid lineage potentials but lack erythroid potential. Myeloid and lymphoid potentials are present at the clonal level in early thymic progenitors, confirming that progenitors settling the thymus include lymphoid-myeloid progenitors. These results revise our view of the T lineage branch of hematopoiesis and focus attention on the generation, circulation, and homing of lymphoid-myeloid progenitors to the thymus.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Chi
authors.forename: J Jeremiah
authors.initials: JJ
authors.lastname: Bell
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Zlotoff
authors.forename: Avinash
authors.initials: A
authors.lastname: Bhandoola
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D019070:Cell Lineage / Q000276:immunology; D006410:Hematopoiesis / Q000276:immunology*; D006801:Humans; D008954:Models, Biological; D013234:Stem Cells / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*