Journal article
DNA methyltransferase 1 and DNA methylation patterning contribute to germinal center B-cell differentiation
Weill Cornell Medical College1
Dana-Farber Cancer Institute2
Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark3
Department of Systems Biology, Technical University of Denmark4
Virginia Commonwealth University5
Karolinska Institutet6
The University of Chicago7
The phenotype of germinal center (GC) B cells includes the unique ability to tolerate rapid proliferation and the mutagenic actions of activation induced cytosine deaminase (AICDA). Given the importance of epigenetic patterning in determining cellular phenotypes, we examined DNA methylation and the role of DNA methyltransferases in the formation of GCs.
DNA methylation profiling revealed a marked shift in DNA methylation patterning in GC B cells versus resting/naive B cells. This shift included significant differential methylation of 235 genes, with concordant inverse changes in gene expression affecting most notably genes of the NFkB and MAP kinase signaling pathways.
GC B cells were predominantly hypomethylated compared with naive B cells and AICDA binding sites were highly overrepresented among hypomethylated loci. GC B cells also exhibited greater DNA methylation heterogeneity than naive B cells. Among DNA methyltransferases (DNMTs), only DNMT1 was significantly up-regulated in GC B cells.
Dnmt1 hypomorphic mice displayed deficient GC formation and treatment of mice with the DNA methyltransferase inhibitor decitabine resulted in failure to form GCs after immune stimulation. Notably, the GC B cells of Dnmt1 hypomorphic animals showed evidence of increased DNA damage, suggesting dual roles for DNMT1 in DNA methylation and double strand DNA break repair.
Language: | English |
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Publisher: | American Society of Hematology |
Year: | 2011 |
Pages: | 3559-3569 |
ISSN: | 15280020 and 00064971 |
Types: | Journal article |
DOI: | 10.1182/blood-2011-06-357996 |
Animals B-Lymphocytes Cell Differentiation Cluster Analysis DNA (Cytosine-5-)-Methyltransferase 1 DNA (Cytosine-5-)-Methyltransferases DNA Methylation DNMT1 protein, human Dnmt1 protein, mouse Epigenesis, Genetic Gene Expression Profiling Germinal Center Humans Mice Mice, Inbred C57BL Mice, Transgenic Microarray Analysis Sheep Validation Studies as Topic