Francesco Vallania,
Postdoctoral Scholar,
ITI, Stanford University

ABSTRACT:
Post-translational modifications of histone proteins and exchanges of histone variants at chromatin are central to the regulation of nearly all DNA-based biological processes. However, the degree and variability of chromatin modifications in specific human immune cells remain largely unknown. Here, we present a highly multiplexed mass cytometry analysis to profile the global levels of a broad array of chromatin modifications in primary human immune cells at the single-cell level. Our data reveal markedly different cell type- and hematopoietic lineage-specific chromatin modification patterns. Differential analysis between younger and older adults shows that aging is associated with increased heterogeneity between individuals and elevated cell-to-cell variability in chromatin modifications. Analysis of a twin cohort unveils heritability of chromatin modifications and demonstrates that aging-related chromatin alterations are predominantly driven by non-heritable influences. We present a powerful platform for chromatin and immunology research. Our discoveries highlight the profound impacts of aging on chromatin modifications.