title: Reversion of B cell commitment upon loss of Pax5 expression.
abstract: The transcription factor Pax5 is essential for initiating B cell lineage commitment, but its role in maintaining commitment is unknown. Using conditional Pax5 inactivation in committed pro-B cells, we demonstrate that Pax5 is required not only to initiate its B lymphoid transcription program, but also to maintain it in early B cell development. As a consequence of Pax5 inactivation, previously committed pro-B cells regained the capacity to differentiate into macrophages in vitro and to reconstitute T cell development in vivo in RAG2-/- mice. Hence, Pax5 expression is continuously required to maintain B cell lineage commitment, because its loss converts committed pro-B cells into hematopoietic progenitors with multilineage potential.
authors.affiliation: Research Institute of Molecular Pathology, Vienna Biocenter, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria.
authors.forename: Ingvild
authors.initials: I
authors.lastname: Mikkola
authors.forename: Barry
authors.initials: B
authors.lastname: Heavey
authors.forename: Markus
authors.initials: M
authors.lastname: Horcher
authors.forename: Meinrad
authors.initials: M
authors.lastname: Busslinger
mesh_terms: D000818:Animals; D018941:Antigens, CD19 / Q000235:genetics / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology*; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D008264:Macrophages / Q000166:cytology / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051757:PAX5 Transcription Factor; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology; D013629:Tamoxifen / Q000031:analogs & derivatives* / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D018941:Antigens, CD19; D004268:DNA-Binding Proteins; D051757:PAX5 Transcription Factor; C497282:Pax5 protein, mouse; D014157:Transcription Factors; D013629:Tamoxifen; C016601:afimoxifene