Prophilactic and long-lasting efficacy of senolytic CAR T cells against age-related metabolic dysfunction.
Senescent cells accumulate in organisms over time as a result of tissue damage and impaired immune surveillance and are thought to contribute to age-related tissue decline1,2. In agreement, genetic ablation studies reveal that elimination of senescent cells from aged tissues can ameliorate various age-related pathologies, including metabolic dysfunction and decreased physical fitness3-7. While small-molecule drugs capable of eliminating senescent cells (known as 'senolytics') partially replicate these phenotypes, many have uncertain mechanisms of action and all require continuous administration to be effective. As an alternative approach, we previously developed a cell-based senolytic therapy based on chimeric antigen receptor (CAR) T cells targeting uPAR, a cell-surface protein upregulated on senescent cells, and showed these can safely and efficiently eliminate senescent cells in young animals and reverse liver fibrosis8. We now show that uPAR-positive senescent cells accumulate during physiological aging and that they can be safely targeted with senolytic CAR T cells in aged animals. Treatment with anti uPAR CAR T cells ameliorates metabolic dysfunction by improving glucose tolerance and exercise capacity in physiological aging as well as in a model of metabolic syndrome. Importantly, the beneficial effects of senolytic CAR T cells are long lasting; single administration of a low dose is sufficient to achieve long-term therapeutic and preventive effects. Overall design: Liver, gonadal adipose tissue and pancreas of 4 aged mice (20 months old; 2 females and 2 males) was dissociated into single cell suspension and subsequently stained for surface uPAR expression. Cells were FACS sorted into uPAR+ and uPAR- populations for each of the organs. After cell sorting the two females and the two males of each organ and population were pooled together so that each organ would have a replicate consisting of 2 pooled male samples and 2 pooled female samples. Single-cell RNAseq was then carried out using 10X Genomics 3' Gene Expression chemistry.