Senescence of T cells

Memory T cells undergo replicative senescence via repetitive proliferation by antigen stimulation, particularly by latently infected viruses such as cytomegalovirus. Senescent T cells have the ability to produce large quantities of pro-inflammatory cytokines and cytotoxic mediators and have been implicated in the pathogenesis of many chronic inflammatory diseases, including cardiovascular diseases. In humans, replicative senescent T cells typically lose expression of CD28 and acquire the expression of CD57; thus, the frequency of CD28null and CD57+ T cells in the peripheral blood increases with age. Recently, we reported evidences that CD8+CD57+ senescent T cells have a role in not only hypertension (Youn JC et al. Hypertension 62:126, 2013) and myocardial infarction (Yu HT et al. Cell Mol Immunol 12:466, 2015) but also vascular aging (Yu HT et al. J Am Heart Assoc 6:e006535, 2017) and hyperglycemia (Lee YH et al. Diabetes 68:156, 2019). Currently, we are studying mechanism how senescent T cells contribute to the pathogenesis of inflammatory diseases and cardiovascular diseases.