Senolytic car t cells as novel therapeutic concept for solid tumors and senescence-associated diseases.
The adoptive transfer of T cells expressing CD19-directed chimeric antigen receptors (CARs) has yielded remarkable efficacy in patients with hematological B-cell malignancies. CARs are a class of synthetic receptors that reprogram T cell specificity, function and metabolism. Engineered T cells are applicable in principle to other cancers and diseases, but clinical success will critically depend on further progress to overcome current limitations such as antigenic heterogeneity or impaired T cell trafficking and function. We propose to develop CAR T cells targeting senescent cells as a novel therapeutic concept for cancer and senescence-associated diseases. Cellular senescence is a stress-response program characterized by stable cell cycle arrest that serves as a potent tumor-suppressive mechanism. Conversely, accumulation of senescent cells generates a chronic inflammatory milieu, which contributes to a plethora of pathologies, such as liver or lung fibrosis and can even promote tumor progression. 
Our preliminary data demonstrate that CAR T cells can efficiently clear senescent cells, providing therapeutic benefit in a murine model of liver fibrosis. We thus firmly believe that senolytic CAR T cells have broad therapeutic potential. To this end, we will apply innovative engineering strategies to develop modular CAR designs tailored to senescence-specific requirements. We will determine safety and efficacy of senolytic CAR T cells in murine models of cellular senescence and solid tumors. Importantly, we will evaluate combined treatment approaches of senescence-inducing therapies with CAR T cells targeting senescent and proliferating tumor cells. Finally, we will investigate engineering tools to optimally direct senolytic CAR activity to mediate durable tumor regression. 
This project combines two emerging concepts of anticancer therapies and goes beyond current applications of CAR therapies. The efforts may lead to promising new therapeutic avenues.