Other - Immunosenescence
Age-associated changes in the functionality of CD4 T cells have been linked to declined immunity and chronic inflammation. Nevertheless, a detailed characterization of CD4 T-cell phenotypes, which may better explain the duality in the deterioration of the immune system in aging, is lacking. By profiling thousands of CD4 T cells from young and old mice via single cell RNA-sequencing and multidimensional protein analysis, we revealed a distinct landscape of CD4 T-cell subsets, including exhausted, cytotoxic, and activated regulatory (aTregs) cells. These three cell subsets are rare early in life and gradually accumulate with age. At the transcriptional and functional level, the aTregs and cytotoxic CD4 subsets exhibit enhanced anti- or pro-inflammatory capability, respectively.Our results provide a comprehensive view of the dynamic reorganization of CD4 T cells with age and illuminate dominant cell subsets associated with declined immunity and chronic inflammation. These findings suggest new therapeutic avenues for age-related diseases.