Methylome of CD4+ T cell subsets
We compared the methylated and non-methylated regions in the genome of ex vivo-isolated naive CD4+ T cells, Th1 cells, Th17 cells and regulatory T cells by methyl-CpG binding domain protein sequencing (MBD-seq). Naive T cells and Th1 cells share more methylated regions than naive T cells and Th17 cells or Th1 and Th17 cells. However, analysis of the non-methylated regions revealed the highest similarity between Th1 and Th17 cells. Another aim was the analysis of the Th17 lineage on the basis of the methylome. We searched for regions absent in the methylome of Th17 but present in naive T cells, Th1 cells and regulatory T cells.  Here, we identified differential methylation in the loci of Il17a, Chn2, Dpp4 and Dclk1. Overall design: CD4+ T effector cells were prepared ex vivo, stimulated with PMA/Ionomycin, subjected to a comercially available cytokine secretion kit (IL-17A and IFNg), stained by adding fluorescence-labeled antibodies against CD3, CD4 and CD45RB and sorted by flow cytometry. We sorted naive CD4+ T cells (CD3+CD4+CD45RB_high), Th1 cells (CD3+CD4+CD45RB_low_IFNg+IL17A-), Th17 cells (CD3+CD4+CD45RB_low_IFNg-IL17A+) and regulatory T cells (CD3+CD4+CD25++).