Senolytic cell therapy identifies and reverses cellular senescence as a driver of aging-associated defects in intestinal regeneration and fitness

Organismal homeostasis is dependent on efficient tissue regeneration. Embedded within the highest self-renewing organ, intestinal stem cells (ISCs) drive the rapid regeneration of the gut epithelium. During aging, however, their regenerative capacity is significantly reduced albeit the exact mechanisms behind this decrease remain to be fully understood. Cellular senescence is a key feature of the aging process; yet little is known about the in vivo presence and functional consequences of senescent cells on the intestinal stem cell niche. Here, we identify, isolate and characterize the accumulation of senescent cells in the murine and human aging guts. To achieve their in vivo targeted ablation, we harness autologous senolytic CAR T cells, and uncover a detrimental impact of senescent cells on ISC function in natural aging and injury. Thus, therapeutic and prophylactic elimination of intestinal senescent cells is sufficient to either rejuvenate or prevent the functional decline in the regenerative potential of aged ISCs resulting in improvements in both epithelial integrity and mucosal immune function. Overall, these findings identify the in vivo deleterious role of senescent cells on the aged intestinal stem cell niche and provide proof of concept of the potential of targeted cell therapies to enhance tissue regeneration in aging organisms. Overall design: Young (3 months) and old (18 months) mice were treated with 0.5x10^6 untransduced T cells (UT) or uPAR CAR T cells (m.uPAR-m.28z). Mice were harvested 8 weeks after infusion and organoids were generated from their intestinal crypts. 5 days after generation, organoids were harvested and subjected to bulk RNA sequencing.