Distinct Age-Related Epigenetic Signatures in CD4 and CD8 T Cells

Area of Science:

• Immunology
• Epigenetics
• Cellular Aging

Background:

• Healthy immune aging depends on maintaining naïve T cell compartments.
• CD4 T cell populations are more stable with age compared to CD8 T cells, which lose naïve cells and gain effector cells.
• This suggests CD4 T cells possess greater resilience to age-related changes.

Purpose of the Study:

• To investigate the epigenetic basis for the differential resilience of CD4 and CD8 T cells during aging.
• To compare chromatin accessibility and gene expression in T cell subsets from young and old individuals.

Main Methods:

• Chromatin accessibility mapping (ATAC-seq) of CD4 and CD8 T cell subsets from young and old adults.
• Transcriptome analysis to correlate epigenetic changes with gene expression.
• Analysis of age-associated epigenetic signatures and their relation to T cell function.

Main Results:

• Age-associated epigenetic signatures, resembling differentiation hallmarks, were more pronounced in CD8 T cells than CD4 T cells.
• CD8 T cells from older adults showed reduced chromatin accessibility in genes related to basic cell functions, including ribosomal proteins.
• Reduced expression of transcription factors YY1 and NRF1 may contribute to these changes in CD8 T cells.

Conclusions:

• Epigenetic differences distinguish CD4 and CD8 T cells in older adults.
• CD4 T cells exhibit greater resilience to aging, potentially due to distinct chromatin accessibility patterns and maintenance of cellular quiescence.
• These findings offer insights into age-related immune dysregulation and potential therapeutic targets.