Comparison of the DNA methylation profiles of CD19+ B lymphocytes of a pair of monozygotic twins discordant for common variable immunodeficiency

The methylation profiles of bisulfite-modified DNA of CD19+ cells from MZ twins discordant for CVID were compared using the Infinium HumanMethylation450 BeadChips (Illumina, Inc., San Diego, CA,). This platform allows the interrogation of >485,000 methylation sites per sample at single-nucleotide resolution, and comprises an average of 17 CpG sites per gene in the 99% of RefSeq genes. 96% of CpG islands are covered, with additional coverage in CpG island shores and the regions flanking them. The samples were hybridized in the array following the manufacturer’s instructions. Total DNA isolated by standard procedures from CD19+ cells (total B lymphocytes) corresponding to two monozygotic twins discordant for common variable immunodeficiency.

本研究采用Infinium HumanMethylation450 BeadChips（Illumina公司，美国加利福尼亚州圣地亚哥），对存在普通可变免疫缺陷症（Common Variable Immunodeficiency, CVID）表型不一致的同卵双生子的CD19+细胞亚硫酸氢盐修饰DNA的甲基化谱进行比较分析。该平台可在单核苷酸分辨率下，对每个样本的逾485,000个甲基化位点进行检测；在99%的RefSeq基因（Reference Sequence Gene）中，每个基因平均覆盖17个CpG位点（CpG site）。96%的CpG岛（CpG island）均被覆盖，同时对CpG岛岸（CpG shore）及其侧翼区域亦具备额外覆盖范围。所有样本均严格按照制造商提供的操作手册完成芯片杂交实验。本研究所用的总DNA通过标准实验流程从CD19+细胞（总B淋巴细胞）中提取，对应两例存在普通可变免疫缺陷症表型不一致的同卵双生子。