TY - JOUR
T1 - DNA methyltransferase 1 and DNA methylation patterning contribute to germinal center B-cell differentiation
AU - Shaknovich, Rita
AU - Cerchietti, Leandro
AU - Tsikitas, Lucas
AU - Kormaksson, Matthias
AU - De, Subhajyoti
AU - Figueroa, Maria E.
AU - Ballon, Gianna
AU - Yang, Shao Ning
AU - Weinhold, Nils
AU - Reimers, Mark
AU - Clozel, Thomas
AU - Luttrop, Karin
AU - Ekstrom, Tomas J.
AU - Frank, Jared
AU - Vasanthakumar, Aparna
AU - Godley, Lucy A.
AU - Michor, Franziska
AU - Elemento, Olivier
AU - Melnick, Ari
PY - 2011/9/29
Y1 - 2011/9/29
N2 - 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.
AB - 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.
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U2 - 10.1182/blood-2011-06-357996
DO - 10.1182/blood-2011-06-357996
M3 - Article
C2 - 21828137
AN - SCOPUS:80053376487
VL - 118
SP - 3559
EP - 3569
JO - Blood
JF - Blood
SN - 0006-4971
IS - 13
ER -