title: Lymphoid priming in human bone marrow begins before expression of CD10 with upregulation of L-selectin.
abstract: Expression of the cell-surface antigen CD10 has long been used to define the lymphoid commitment of human cells. Here we report a unique lymphoid-primed population in human bone marrow that was generated from hematopoietic stem cells (HSCs) before onset of the expression of CD10 and commitment to the B cell lineage. We identified this subset by high expression of the homing molecule L-selectin (CD62L). CD10(-)CD62L(hi) progenitors had full lymphoid and monocytic potential but lacked erythroid potential. Gene-expression profiling placed the CD10(-)CD62L(hi) population at an intermediate stage of differentiation between HSCs and lineage-negative (Lin(-)) CD34(+)CD10(+) progenitors. CD62L was expressed on immature thymocytes, and its ligands were expressed at the cortico-medullary junction of the thymus, which suggested a possible role for this molecule in homing to the thymus. Our studies identify the earliest stage of lymphoid priming in human bone marrow.
authors.affiliation: Department of Pathology & Laboratory Medicine, University of California, Los Angeles, California, USA.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kohn
authors.forename: Qian-Lin
authors.initials: QL
authors.lastname: Hao
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Sasidharan
authors.forename: Chintan
authors.initials: C
authors.lastname: Parekh
authors.forename: Shundi
authors.initials: S
authors.lastname: Ge
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Zhu
authors.forename: Hanna K A
authors.initials: HK
authors.lastname: Mikkola
authors.forename: Gay M
authors.initials: GM
authors.lastname: Crooks
mesh_terms: D018952:Antigens, CD34 / Q000276:immunology / Q000378:metabolism; D019011:Antigens, CD7 / Q000276:immunology; D001854:Bone Marrow Cells / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D019041:L-Selectin / Q000096:biosynthesis*; D015260:Neprilysin / Q000096:biosynthesis*; D060168:Thymocytes / Q000276:immunology / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D018952:Antigens, CD34; D019011:Antigens, CD7; D019041:L-Selectin; D015260:Neprilysin