CAR T cells targeting uPAR are effective senolytics

Cellular senescence is a stress-response program characterized by stable cell cycle arrest and a secretory program that modulates the tissue microenvironment. Physiologically, senescence serves as a potent tumor suppressive mechanism that prevents the expansion of premalignant cells and plays a beneficial role in certain wound healing responses. Pathologically, the aberrant accumulation of senescent cells in response to chronic tissue damage produces an inflammatory milieu that contributes to diseases such as liver and lung fibrosis, atherosclerosis, diabetes and osteoarthritis. Accordingly, experimental approaches to eliminate senescent cells from damaged tissues in mice can ameliorate symptoms of these pathologies and even promote longevity. Here we test the therapeutic concept that chimeric antigen receptor (CAR) T cells targeting senescent cells can serve as effective senolytics. We identify the urokinase plasminogen activator receptor (uPAR) as a cell surface protein that is broadly induced during senescence and demonstrate that uPAR-specific CAR T cells efficiently target senescent cells in vitro and in vivo. Administration of uPAR-targeting CAR T cells improves the survival of mice harboring lung adenocarcinoma cells treated with a senescence inducing drug combination, and eliminates fibrosis in mice treated with carbon tetrachloride or on a non-alcoholic steatohepatitis (NASH)-inducing diet. These results establish the potential of senolytic CAR T therapy for a range of senescence-associated diseases. Overall design: Characterization of the transcriptional profiles of both murine therapy and oncogene induced senescence. For therapy induced senescence murine lung adenocarcinoma cell lines (KRASG12D,Tp53-/-) were cultured for 8 days with either DMSO or combined MEK and Cdk4/6 inhibitors to induce senescence. To study oncogene induced senescence hydrodynamic tail vein injection was performed to overexpress NRASG12V in murine hepatocytes and induce senescence.