Accumulation of CD8 T cells memory subsets expressing inhibitory receptors in the adipose tissue of aged mice 3871

Abstract Description Aging and obesity have been linked to driving inflammatory changes in adipose tissue. Similar mechanisms, such as the infiltration of inflammatory macrophages and T cells into visceral adipose tissue, have been suggested to contribute to these inflammatory changes. Recent studies have identified exhausted PD1+ CD8 T cells in the visceral adipose tissue of both aged and obese mice suggested to be involved in the inflammation. In our study, we used single-cell sequencing to explore the heterogeneity of visceral adipose tissue during aging compared to obesity. We isolated stromal vascular fractions (SVF) from the gonadal white adipose tissue of young (4–5 months) mice fed either a normal or a high-fat diet, and from aged (21–22 months) mice fed a normal diet. Our observations revealed accumulation of B cells and T cells in the SVF of aged mice. Specifically, CD8 T cells from the SVF exhibited increased incoming signaling from various cells (high number of Ligand-receptor pairs), which was more pronounced in aged mice compared to those fed a high-fat or normal diet. Further investigation of CD8 T cells showed the accumulation of previously defined age-associated PD1+ Gzmk+ CD8 T cells, along with CD44+CD62L+CD122+CD49d- central/virtual memory phenotype in the adipose tissue of aged mice. The expression profiles of these cells revealed the presence of different inhibitory receptors among various memory CD8 T cells, potentially affecting the functionality of the CD8 T memory cell. Funding Sources Supported by NIAID R01AI162787 Topic Categories Cellular Adhesion, Migration, and Inflammation (CAM)