TitleDNA methyltransferase 1 and DNA methylation patterning contribute to germinal center B-cell differentiation.
Publication TypeJournal Article
Year of Publication2011
AuthorsShaknovich, Rita, Cerchietti Leandro, Tsikitas Lucas, Kormaksson Matthias, De Subhajyoti, Figueroa Maria E., Ballon Gianna, Yang Shao Ning, Weinhold Nils, Reimers Mark, Clozel Thomas, Luttrop Karin, Ekstrom Tomas J., Frank Jared, Vasanthakumar Aparna, Godley Lucy A., Michor Franziska, Elemento Olivier, and Melnick Ari
Date Published2011 Sep 29
KeywordsAnimals, B-Lymphocytes, Cell Differentiation, Cluster Analysis, DNA (Cytosine-5-)-Methyltransferase 1, DNA (Cytosine-5-)-Methyltransferases, DNA Methylation, Epigenesis, Genetic, Gene Expression Profiling, Germinal Center, Humans, Mice, Mice, Inbred C57BL, Mice, Transgenic, Microarray Analysis, Sheep, Validation Studies as Topic

<p>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.</p>

Alternate JournalBlood
PubMed ID21828137
PubMed Central IDPMC3186332
Grant ListU54 CA143798 / CA / NCI NIH HHS / United States
R01 CA129831 / CA / NCI NIH HHS / United States
R01CA138234 / CA / NCI NIH HHS / United States
CA129831-03S1 / CA / NCI NIH HHS / United States
K08 CA127353 / CA / NCI NIH HHS / United States
CA129831 / CA / NCI NIH HHS / United States
U54CA143798 / CA / NCI NIH HHS / United States
R01 CA138234 / CA / NCI NIH HHS / United States