Age-associated alterations in pro-inflammatory gene expression in humans

National Institute On Aging

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Abstract

The goal of the first phase of GESTALT was to obtain transcriptomic, proteomic and epigenomic data from 11 purified immune cell subsets obtained from peripheral blood of 100 healthy individuals across the age range from 20s-80. Sample collection for this phase was completed in February 2020. In the next 3 years we collected samples from approximately 50 returning donors for analysis of metabolism, and assays of lymphocyte activation. Finally, ongoing sample collection is aimed at restoring numbers of phase donors to account for close to 40% attrition frequency for second visits. During FY25 we accomplished the following: 1) We completed analyses of age-associated transcriptomic changes in human immune cells. Three different analytic approaches yielded distinct patters of age-associated changes. These observations are ready to be submitted for publication. 2) We completed studies of human monocyte aging by increasing cohort size to understand the basis of constitutive cytokine expression (at protein level) in a subset of healthy donors. 3) We submitted for a publication a study investigating changes in methylation, gene expression and chromatin structure during lymphocyte memory differentiation. We found that in vitro proliferation was sufficient to induce memory-like characteristics in CD4+ T cells but not B cells. However, the manuscript is back and being revised into two manuscripts that investigate B and T cell memory formation independently. For this we are delving onto the data in much greater detail than in the original submission with the goal of ascertaining the relative contributions of DNA methylation and chromatin accessibility to establishing the functional phenotype of adaptive immune memory. 4) We carried out 6-base sequencing naïve and memory B and CD4+T cells. Preliminary analysis indicated that sequencing had not been adequately performed. Thus, sequencing data were re-acquired and is being re-analyzed. 5) We developed the procedure and carried out EU-Seq to examine transcriptional changes during human memory differentiation. 6) We established experimental conditions to carry single cell multiome analyses on activated T cells and monocytes from peripheral human blood. The goal is to investigate functional phenotypes of immune aging at the single cell level and underlying mechanisms.