E-Poster with pre-recorded video presentation Lorne Infection and Immunity 2021

Age related epigenetic changes associated with and causative of intrinsic CD8+ T cell dysfunction (#203)

Daniel Thiele 1 2 , Adele Barugahare 2 3 , Angela Nguyen 1 2 , Taylah Bennett 2 3 , Tabinda Hussain 1 2 , Pirooz Zareie 2 3 , Vibha Udupa 2 3 , Kylie Quinn 4 , Brendan Russ 2 3 , Jasmin Li 2 3 , Stephen Turner 2 3 , Nicole La Gruta 1 2
  1. Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
  2. Monash Biomedicine Discovery Institute, Monash Univeristy, Clayton, Victoria, Australia
  3. Department of Microbiology, Monash University, Clayton, Victoria, Australia
  4. School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia

A quarter of the world’s population will be >60 years of age by 2050. More must be done to understand the intricacies associated with age-related pathology as we rapidly approach an aged society. With aging there is decrease in peripheral naïve CD8+ T cells with a simultaneous increase in CD44hi memory CD8+ T cells. Virtual-Memory T (Tvm) cells  are antigen-naïve T cells that present a classical memory phenotype whilst also possessing innate-like immune function. Unlike other CD8 subsets, Tvm cell homeostasis is highly dependent on cytokines, as shown by their selective depletion in IL-15-/- mice. Tvm cells acquire TCR-associated defects in aged mice and humans, which could contribute to the overall decline in CD8 T cell function seen with aging. Tvm cells make up a large proportion of the naïve CD8+ T cell pool making them ideal targets for age specific therapeutic interventions. Here, we have performed ATAC-Seq analysis on young and aged CD8+ T cell subsets and have identified several key signatures selectively associated with age-related dysfunction. The aged-specific Tvm cell signature will be validated and the role of candidate genes involved in mediating the dysfunction assessed using a range of molecular and cellular techniques. Validated targets will be investigated for the capacity to block their inhibitory effects to mediate functional recovery in dysfunctional T cells. Collectively, this study will provide fundamental information on biological changes associated with advanced age in CD8+ T cells, which is essential for informed targeting to rejuvenate cellular immunity in the elderly.