A well-balanced population of pathogenic T (Tpath) and regulatory T (Treg) cells is important for maintaining immune tolerance and preventing autoimmune diseases. However, the molecular mechanisms modulating Tpath or Treg functional differentiation remain largely unclear. Using methylated CpG island recovery assay (MIRA), we have analyzed DNA methylation profiling in one Tpath, two Tregs and one control T cell line (Tctrl). We have identified a total of 2204 different methylation peaks in the four cells and ~1300 peaks in each cell. Analyses of autosomes in Tpath showed relatively lower methylation density than those in Tregs, except for Chromsome 19 that has similar methylation density. Furthermore, 63 hypermethylation and 268 hypomethylation peaks were uniquely found in Tpath, compared to 323 hypermethylation and 30 hypomethylation unique peaks in Tregs. However, the methylation density of Chromosome X in Tpath is significantly higher than that in Tregs. In summary, opposite epigenetic mechanisms are likely involved in methylation of genes on autosomes or Chromosome X in Tpaths and Tregs, thus contributing to the functional differentiation/specification between Tpaths and Tregs.
Jianying Shen, Qingsheng Yu, Xiaoqiang Li, Rujing Ren and Yuqing Tan