Cutting Edge: Polycomb Gene Expression Patterns Reflect Distinct B Cell Differentiation Stages in Human Germinal Centers

• Published in: The Journal of immunology (1950) Vol. 164; no. 1; pp. 1 - 4
• Main Authors: Raaphorst, Frank M, van Kemenade, Folkert J, Fieret, Elly, Hamer, Karien M, Satijn, David P. E, Otte, Arie P, Meijer, Chris J. L. M
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01-01-2000
• Subjects: B-Lymphocyte Subsets - cytology; B-Lymphocyte Subsets - metabolism; Cell Differentiation - immunology; DNA-Binding Proteins - biosynthesis; Gene Expression Regulation, Developmental - immunology; Genes, Homeobox - immunology; Germinal Center - cytology; Germinal Center - metabolism; Humans; Nuclear Proteins - biosynthesis; Polycomb Repressive Complex 1; Polycomb Repressive Complex 2; Polycomb-Group Proteins; Proto-Oncogene Proteins - biosynthesis; Repressor Proteins - biosynthesis; Repressor Proteins - genetics
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.164.1.1

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.