title: The common myelolymphoid progenitor: a key intermediate stage in hemopoiesis generating T and B cells.
abstract: We have previously shown that the common progenitors for myeloid, T, and B cell lineages are enriched in the earliest population of murine fetal liver. However, it remained unclear whether such multipotent progenitors represent the pluripotent progenitors capable of generating all hemopoietic cells or they also comprise progenitors restricted to myeloid, T, and B cell lineages. To address this issue, we have developed a new clonal assay covering myeloid, erythroid, T, and B cell lineages, and using this assay the developmental potential of individual cells in subpopulations of lineage marker-negative (Lin(-)) c-kit(+) murine fetal liver cells was investigated. We identified the progenitor generating myeloid, T, and B cells, but not erythroid cells in the Sca-1(high) subpopulation of Lin(-)c-kit(+) cells that can thus be designated as the common myelolymphoid progenitor (CMLP). Common myeloerythroid progenitors were also detected. These findings strongly suggest that the first branching point in fetal hemopoiesis is between the CMLP and common myeloerythroid progenitors. T and B cell progenitors may be derived from the CMLP through the previously identified myeloid/T and myeloid/B bipotent stages, respectively.
authors.affiliation: Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Min
authors.initials: M
authors.lastname: Lu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawamoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Katsube
authors.forename: Tomokatsu
authors.initials: T
authors.lastname: Ikawa
authors.forename: Yoshimoto
authors.initials: Y
authors.lastname: Katsura
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D019070:Cell Lineage / Q000235:genetics / Q000276:immunology; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D005333:Fetus; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental / Q000276:immunology; D006410:Hematopoiesis / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D023461:Myeloid Progenitor Cells / Q000145:classification / Q000166:cytology* / Q000276:immunology*; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; D019009:Proto-Oncogene Proteins c-kit