The proposed project will examine age-associated changes in gene expression and epigenetic state of 10 cell subsets purified from human peripheral blood. This is a collaborative venture that involves several NIA/IRP laboratories, including, LMBI, TGB, LMG, and LG. Cytapheresis packs will be collected from 30 volunteers of varying age-groups and cells fractioned by a combination of magnetic bead purification and flow cytometry. These cells will be used to isolate RNA and carry out ChIP and ATAC. Purified RNA and DNA will be provided to Dr. Hao for deep sequencing. Additionally, ChIA-Pet will be used to obtain chromatin structural information. ATAC and ChIA-Pet libraries will be prepared at the NIA and provided to the contractor.