CD4 + and CD8 + T-Cell-Specific DNA Cytosine Methylation Differences Associated With Obesity.

OBJECTIVE: Lifestyle factors associated with obesity may alter epigenome-regulated gene expression. Most studies examining epigenetic changes in obesity have analyzed DNA 5´-methylcytosine (5mC) in whole blood, representing a weighted average of several distantly related and regulated leukocyte classes. To examine leukocyte-specific differences associated with obesity, a pilot study examining 5mC in three distinct leukocyte types isolated from peripheral blood of women with normal weight and obesity was conducted.

METHODS: CD4+ T cells, CD8+ T cells, and CD16+ neutrophils were reiteratively isolated from blood, and 5mC levels were measured across >450,000 CG sites.

RESULTS: Nineteen CG sites were differentially methylated between women with obesity and with normal weight in CD4+ cells, 16 CG sites in CD8+ cells, and 0 CG sites in CD16+ neutrophils (q < 0.05). There were no common differentially methylated sites between the T-cell types. The amount of visceral adipose tissue was strongly associated with the methylation level of 79 CG sites in CD4+ cells, including 4 CG sites in CLSTN1's promoter, which, this study shows, may regulate its expression.

CONCLUSIONS: The methylomes of various leukocytes respond differently to obesity and levels of visceral adipose tissue. Highly significant differentially methylated sites in CD4+ and CD8+ cells in women with obesity that have apparent biological relevance to obesity were identified.