title: Cutting edge: polycomb gene expression patterns reflect distinct B cell differentiation stages in human germinal centers.
abstract: Polycomb group (Pc-G) proteins regulate homeotic gene expression in Drosophila, mouse, and humans. Mouse Pc-G proteins are also essential for adult hematopoietic development and contribute to cell cycle regulation. We show that human Pc-G expression patterns correlate with different B cell differentiation stages and that they reflect germinal center (GC) architecture. The transition of resting mantle B cells to rapidly dividing Mib-1(Ki-67)+ follicular centroblasts coincides with loss of BMI-1 and RING1 Pc-G protein detection and appearance of ENX and EED Pc-G protein expression. By contrast, differentiation of centroblasts into centrocytes correlates with reappearance of BMI-1/RING1 and loss of ENX/EED and Mib-1 expression. The mutually exclusive expression of ENX/EED and BMI-1/RING1 reflects the differential composition of two distinct Pc-G complexes. The Pc-G expression profiles in various GC B cell differentiation stages suggest a role for Pc-G proteins in GC development.
authors.affiliation: Department of Pathology, Vrÿe Universiteit University Hospital, Amsterdam, The Netherlands. fm.raaphorst@azvu.nl
authors.forename: F M
authors.initials: FM
authors.lastname: Raaphorst
authors.forename: F J
authors.initials: FJ
authors.lastname: van Kemenade
authors.forename: E
authors.initials: E
authors.lastname: Fieret
authors.forename: K M
authors.initials: KM
authors.lastname: Hamer
authors.forename: D P
authors.initials: DP
authors.lastname: Satijn
authors.forename: A P
authors.initials: AP
authors.lastname: Otte
authors.forename: C J
authors.initials: CJ
authors.lastname: Meijer
mesh_terms: D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation / Q000276:immunology; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental / Q000276:immunology*; D005801:Genes, Homeobox / Q000276:immunology*; D018858:Germinal Center / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D009687:Nuclear Proteins / Q000096:biosynthesis; D063150:Polycomb Repressive Complex 1; D063151:Polycomb Repressive Complex 2; D063146:Polycomb-Group Proteins; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C069077:BMI1 protein, human; C489421:Bmi1 protein, mouse; D004268:DNA-Binding Proteins; C491488:EED protein, human; D009687:Nuclear Proteins; D063146:Polycomb-Group Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D063151:Polycomb Repressive Complex 2; D063150:Polycomb Repressive Complex 1; C080355:RING1 protein, human; C489840:Ring1 protein, mouse