title: A reporter mouse reveals lineage-specific and heterogeneous expression of IRF8 during lymphoid and myeloid cell differentiation.
abstract: The IFN regulatory factor family member 8 (IRF8) regulates differentiation of lymphoid and myeloid lineage cells by promoting or suppressing lineage-specific genes. How IRF8 promotes hematopoietic progenitors to commit to one lineage while preventing the development of alternative lineages is not known. In this study, we report an IRF8-EGFP fusion protein reporter mouse that revealed previously unrecognized patterns of IRF8 expression. Differentiation of hematopoietic stem cells into oligopotent progenitors is associated with progressive increases in IRF8-EGFP expression. However, significant induction of IRF8-EGFP is found in granulocyte-myeloid progenitors and the common lymphoid progenitors but not the megakaryocytic-erythroid progenitors. Surprisingly, IRF8-EGFP identifies three subsets of the seemingly homogeneous granulocyte-myeloid progenitors with an intermediate level of expression of EGFP defining bipotent progenitors that differentiation into either EGFP(hi) monocytic progenitors or EGFP(lo) granulocytic progenitors. Also surprisingly, IRF8-EGFP revealed a highly heterogeneous pre-pro-B population with a fluorescence intensity ranging from background to 4 orders above background. Interestingly, IRF8-EGFP readily distinguishes true B cell committed (EGFP(int)) from those that are noncommitted. Moreover, dendritic cell progenitors expressed extremely high levels of IRF8-EGFP. Taken together, the IRF8-EGFP reporter revealed previously unrecognized subsets with distinct developmental potentials in phenotypically well-defined oligopotent progenitors, providing new insights into the dynamic heterogeneity of developing hematopoietic progenitors.
authors.affiliation: Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; hmorse@niaid.nih.gov wanghongs@niaid.nih.gov.
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Wang
authors.affiliation: Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892;
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852;
authors.forename: Jiafang
authors.initials: J
authors.lastname: Sun
authors.affiliation: Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852;
authors.forename: Shweta
authors.initials: S
authors.lastname: Jain
authors.affiliation: Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan;
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Yoshimi
authors.affiliation: Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852;
authors.forename: Sanaz Momben
authors.initials: SM
authors.lastname: Abolfath
authors.affiliation: Program in Genomics of Differentiation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;
authors.forename: Keiko
authors.initials: K
authors.lastname: Ozato
authors.affiliation: Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892;
authors.forename: William G
authors.initials: WG
authors.lastname: Coleman
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Ashley P
authors.initials: AP
authors.lastname: Ng
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Donald
authors.initials: D
authors.lastname: Metcalf
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; and.
authors.forename: Ladina
authors.initials: L
authors.lastname: DiRago
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Nutt
authors.affiliation: Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; hmorse@niaid.nih.gov wanghongs@niaid.nih.gov.
authors.forename: Herbert C
authors.initials: HC
authors.lastname: Morse
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology; D002454:Cell Differentiation / Q000276:immunology; D019070:Cell Lineage / Q000276:immunology; D017930:Genes, Reporter; D005838:Genotype; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology; D049452:Green Fluorescent Proteins / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology; D050835:Interferon Regulatory Factors / Q000096:biosynthesis / Q000235:genetics*; D007377:Interleukin-3 / Q000494:pharmacology; D038041:Lymphopoiesis / Q000276:immunology*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D022423:Myeloid Cells / Q000166:cytology; D038042:Myelopoiesis / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013601:T-Lymphocytes / Q000166:cytology; D000099185:Interferon Regulatory Factor-8
chemical_list: D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D049452:Green Fluorescent Proteins; D050835:Interferon Regulatory Factors; D007377:Interleukin-3; D016173:Macrophage Colony-Stimulating Factor; D011993:Recombinant Fusion Proteins; D000099185:Interferon Regulatory Factor-8; C485184:enhanced green fluorescent protein