A multipotent precursor in the thymus maps to the branching point of the T versus B lineage decision.
Hematopoietic precursors continuously colonize the thymus where they give rise mainly to T cells, but also to B and dendritic cells. The lineage relationship between these three cell types is unclear, and it remains to be determined if precursors in the thymus are multipotent, oligopotent, or lineage restricted. Resolution of this question necessitates the determination of the clonal differentiation potential of the most immature precursors in the thymus. Using a CC chemokine receptor 9-enhanced green fluorescent protein knock-in allele like a surface marker of unknown function, we identify a multipotent precursor present in bone marrow, blood, and thymus. Single cells of this precursor give rise to T, B, and dendritic cells. A more differentiated stage of this multipotent precursor in the thymus has lost the capacity to generate B but not T, dendritic, and myeloid cells. Thus, the newly identified precursor maps to the branching point of the T versus B lineage decision in the hematopoietic lineage hierarchy.
Department of Developmental Immunology, Max-Planck-Institute for Immunobiology, 79108 Freiburg, Germany.
Claudia
C
Benz
Conrad C
CC
Bleul
D019264:Adoptive Transfer; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D002454:Cell Differentiation; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000276:immunology; D054388:Receptors, CCR; D019707:Receptors, Chemokine / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology
C119309:CC chemokine receptor 9; D054388:Receptors, CCR; D019707:Receptors, Chemokine; D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins